祸首

Traditional form:

禍首

Pinyin (reading):

huòshǒu

Definitions:

• chief offender
• main culprit

Characters:

• 祸 - misfortune, disaster, calamity
• 首 - chief, head, leader

Traditional characters:

• 禍 - misfortune, disaster, calamity
• 首 - chief, head, leader