Pronunciation: (sem'ē, sem'ī), [key]
1. semitrailer (def. 1).
2. Often, semis. semifinal (def. 3).
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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.