the GNU version of the Collaborative International Dictionary of English
adj. Containing, or consisting of, three languages; expressed in three languages.
The Century Dictionary and Cyclopedia
Consisting of or expressed in three languages.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. using or knowing three languages
Word Usage
"It was assumed earlier that differences in the brain would only occur if a person is bi - or trilingual, that is with a very high command of different languages."