墨

surname Mo / abbr. for 墨西哥[Mo4 xi1 ge1], Mexico

ink stick / China ink / CL:塊|块[kuai4] / corporal punishment consisting of tattooing characters on the victim's forehead

Tu (ethnic group) / surname Tu

earth / dust / clay / local / indigenous / crude opium / unsophisticated / one of the eight categories of ancient musical instruments 八音[ba1 yin1]

abbr. for Heilongjiang province 黑龍江|黑龙江[Hei1 long2 jiang1]

black / dark / sinister / secret / shady / illegal / to hide (sth) away / to vilify / (loanword) to hack (computing)