Usage of the character 私

personal
private
selfish

sīmài

私卖

[私賣]

to sell illicitly
to bootleg
to sell privately

sīyù

私欲

[私欲]

selfish desire

sīniàng

私酿

[私釀]

to brew alcoholic drinks illegally

yīnsī

因私

[因私]

private (i.e. not work-related 因公 (yīngōng))

sīfú

私服

[私服]

(gaming) server emulator; private server (abbr. for 私人服務器／私人服务器 (sīrénfúwùqì))

sīnáng

私囊

[私囊]

one's own pocket

sīchuǎng

私闯

[私闖]

to enter (a place) without permission; to intrude into

fànsī

贩私

[販私]

to traffic (smuggled goods)
illegal trading

sītūn

私吞

[私吞]

to misappropriate (public funds etc)
to embezzle

sīqíng

私情

[私情]

personal considerations
love affair

sīyíng

私营

[私營]

privately-owned
private

sīmì

私秘

[私秘]

variant of 私密 (sīmì)

sīyǔ

私语

[私語]

to discuss in whispered tones
whispered conversation

sījiào

私教

[私教]

personal trainer

sīlì

私立

[私立]

privately-run; private (school, hospital etc)
to set up illegally

sīchù

私处

[私處]

private parts
genitalia

sīxíng

私行

[私行]

to travel on private business
to act without official approval
to inspect incognito
to act in one's own interest

sītōng

私通

[私通]

to have secret ties with
to be in covert communication with (the enemy etc)
to engage in an illicit sexual relationship
adultery

sīliǎo

私了

[私了]

to settle privately
to solve behind closed doors
to settle out of court

sīfang

私房

[私房]

personal
private
confidential

sīhuì

私会

[私會]

(of lovers) to meet in secret; to have a clandestine rendezvous

sīyǒu

私有

[私有]

private
privately-owned

sīdì

私第

[私第]

(literary) private residence; private house

sīshú

私塾

[私塾]

private school (in former times)

sībēn

私奔

[私奔]

to elope

sīzhái

私宅

[私宅]

private residence

sīmù

私募

[私募]

private placement (investing)

sījiā

私家

[私家]

private
privately owned or managed

jiāsī

家私

[家私]

family property
family wealth

sīyán

私盐

[私鹽]

illegally-traded salt (with salt tax not paid)

sījiāo

私交

[私交]

personal friendship

zǒusī

走私

[走私]

to smuggle
to have an illicit affair

sīyùn

私运

[私運]

to smuggle

zìsī

自私

[自私]

selfish
selfishness

cángsī

藏私

[藏私]

(Tw) to withhold (knowledge, resources etc) out of reluctance to share

sīxìn

私信

[私信]

private correspondence; personal letter
(computing) personal message (PM); to message sb

sīshòu

私售

[私售]

see 私賣／私卖 (sīmài)

sīlüè

私掠

[私掠]

to privateer

sīxià

私下

[私下]

in private

sīcáng

私藏

[私藏]

to keep hidden
to keep in one's private possession
secret store
stash

sīshì

私事

[私事]

personal matters

sīrén

私人

[私人]

private
personal
interpersonal
sb with whom one has a close personal relationship
a member of one's clique

sīchóu

私仇

[私仇]

personal grudge

sīfǎ

私法

[私法]

private law

sībàn

私办

[私辦]

privately-run

sīlì

私利

[私利]

personal gain; (one's own) selfish interest

sīliáo

私聊

[私聊]

(computing) to chat privately; private chat

sīyào

私钥

[私鑰]

(cryptography) private key

sīpiān

私偏

[私偏]

selfish preference

sīmì

私密

[私密]

private
secret
intimate

gōngsī

公私

[公私]

public and private (interests, initiative etc)

yíngsī

营私

[營私]

to gain from corrupt dealing
to engage in graft
to feather one's nest

sīzì

私自

[私自]

private; personal
secretly; without explicit approval

sīdǐ

私邸

[私邸]

private residence of a high-ranking official (as distinct from an official residence)

sīqǐ

私企

[私企]

private enterprise
abbr. of 私營企業／私营企业 (sīyíngqǐyè)

sīfáng

私房

[私房]

privately-owned house
private rooms
private ownings

wúsī

无私

[無私]

selfless
unselfish
disinterested
altruistic

yǐnsī

隐私

[隱私]

secrets
private business
privacy

yīnsī

阴私

[陰私]

shameful secret

sīchǎn

私产

[私產]

private property

sībì

私弊

[私弊]

fraudulent practice

sīfèn

私愤

[私憤]

personal spite
malice

sīxīn

私心

[私心]

selfishness
selfish motives

piānsī

偏私

[偏私]

to practice favoritism

sīxùn

私讯

[私訊]

(Tw) private message
to send a private message

jīsī

缉私

[緝私]

to suppress smugglers
to search for smuggled goods

sīyǐn

私隐

[私隱]

(HK) privacy

sīshēnghuó

私生活

[私生活]

private life

sījiāchē

私家车

[私家車]

private car

sīfángqián

私房钱

[私房錢]

secret purse
secret stash of money

sīyǒuzhì

私有制

[私有制]

private ownership of property

bǎosīnáng

饱私囊

[飽私囊]

to stuff one's pockets
to enrich oneself dishonestly

sīyǒuhuà

私有化

[私有化]

privatization
to privatize

sīshēngzǐ

私生子

[私生子]

illegitimate son

fǎnzǒusī

反走私

[反走私]

to oppose smuggling
anti-contraband (measures, policy etc)

zǒusīhuò

走私货

[走私貨]

smuggled goods

sīshēngnü

私生女

[私生女]

illegitimate daughter

yǐnsīquán

隐私权

[隱私權]

privacy right

sīdǐxia

私底下

[私底下]

privately
secretly
confidentially

xièsīfèn

泄私愤

[洩私憤]

to vent personal spite
to act out of malice (esp. of crime)

shuǎsīqíng

耍私情

[耍私情]

the play of passions
carried away by passion (e.g. to commit a crime)

zǒusīpǐn

走私品

[走私品]

smuggled product
contraband
pirate product

yíngsīwǔbì

营私舞弊

[營私舞弊]

see 徇私舞弊 (xùnsī-wǔbì)

tiěmiànwúsī

铁面无私

[鐵面無私]

strictly impartial and incorruptible (idiom)

gōngsījiāngù

公私兼顾

[公私兼顧]

to adequately take into account both public and private interests

sīshēngzǐnü

私生子女

[私生子女]

illegitimate child

guānsīhéyíng

官私合营

[官私合營]

public and private interests working together (idiom)

gōng'érwàngsī

公而忘私

[公而忘私]

for the common good and forgetting personal interests (idiom); to behave altruistically
selfless

sǔngōngféisī

损公肥私

[損公肥私]

to damage the public interest for personal profit (idiom); personal profit at public expense
venal and selfish behavior

wēifúsīfǎng

微服私访

[微服私訪]

to mingle with the people incognito

guójìsīfǎ

国际私法

[國際私法]

conflict of laws

gōngbàosīchóu

公报私仇

[公報私仇]

to use public office to avenge private wrongs

qièqièsīyǔ

窃窃私语

[竊竊私語]

(idiom) to whisper

xùnsīwǔbì

徇私舞弊

[徇私舞弊]

(idiom) to abuse one's position for personal gain

dòusīpīxiū

斗私批修

[鬥私批修]

fight self-interest and repudiate revisionism (Cultural Revolution slogan)

zhōngbǎosīnáng

中饱私囊

[中飽私囊]

to stuff one's pockets
to take bribes

jiǎgōngjìsī

假公济私

[假公濟私]

official authority used for private interests (idiom); to attain private ends by abusing public position

sīyíngqǐyè

私营企业

[私營企業]

private business
opposite: state-owned enterprise 國有企業／国有企业 (guóyǒuqǐyè)

gōngsīhéyíng

公私合营

[公私合營]

joint public private operation

gèrényǐnsī

个人隐私

[個人隱私]

personal privacy; private matters

guānbàosīchóu

官报私仇

[官報私仇]

to take advantage of official post for personal revenge (idiom)

zìsīzìlì

自私自利

[自私自利]

everything for self and selfish profit (idiom); with no regard for others
selfish
mercenary

xùnsīwǎngfǎ

徇私枉法

[徇私枉法]

to bend the law in order to favor one's relatives or associates (idiom)

qièqièsīyǔ

切切私语

[切切私語]

a private whisper

yǐquánmóusī

以权谋私

[以權謀私]

to use one's position for personal gain (idiom)

sīmùjījīn

私募基金

[私募基金]

private equity fund
fund offered to private placement (e.g. hedge fund)

sīlìxuéxiào

私立学校

[私立學校]

private school

chuángzǐzhīsī

床笫之私

[床笫之私]

intimate matters

jiédǎngyíngsī

结党营私

[結黨營私]

(idiom) to form a clique for self-serving purposes

sīrényàoshi

私人钥匙

[私人鑰匙]

private key (in encryption)

sīdìngzhōngshēn

私定终身

[私定終身]

to make a pledge to be married, without parents' approval

dàgōngwúsī

大公无私

[大公無私]

selfless
impartial

wūniǎosīqíng

乌鸟私情

[烏鳥私情]

lit. the solicitude of the crow (who provides for his old parent)(idiom)
fig. filial piety

sīrénfúwùqì

私人服务器

[私人服務器]

(gaming) server emulator; private server

xūnǐsīrénwǎngluò

虚拟私人网络

[虛擬私人網絡]

virtual private network (VPN)