Synonyms for Semi (same or very similar meaning)
WordNet sense 1 (one of the two competitions in the next to the last round of an elimination tournament):
semifinal
WordNet sense 2 (a truck consisting of a tractor and trailer together):
rig, trailer truck, articulated lorry, tractor trailer, trucking rig
WordNet sense 3 (a trailer having wheels only in the rear; the front is supported by the towing vehicle):
semitrailer
From the ODE community, based on WordNet
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