Dictionary
source' lan"guage
1. the language in which a text appears that is to be translated into another language. Cf.
target language (def. 1).
2. a language, usually the learner's native language, that is a source of interference in learning another language. Cf.
target language (def. 2).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.