相干 Traditional form: 相干 Pinyin (reading): xiānggān Definitions: relevant to have to do with (physics) (of light etc) coherent Characters: 相 - mutual, reciprocal; equal; each other 干 - arid, dry; to oppose; to offend; to invade Traditional characters: 相 - mutual, reciprocal; equal; each other 干 - arid, dry; to oppose; to offend; to invade