semi- a combining form borrowed from Latin, meaning “half,” freely prefixed to English words of any origin, now sometimes with the senses “partially,” “incompletely,” “somewhat”: semiautomatic; semidetached; semimonthly; semisophisticated.

What is semi slang for?

(slang) A partial erection. quotations ▼

Does Semi mean 2?

Bimonthly vs. Semimonthly

Bi- is a prefix meaning two or twice; semi- is a prefix meaning half. There is debate surrounding the actual definition of bi- being both two and twice, although semi- is always half.