Definition of "colloquial" [col•lo•qui•al]

• Characteristic of or appropriate to the spoken language or to writing that seeks the effect of speech; informal. (adjective)
• Relating to conversation; conversational. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "But once it was realized that both speech and writing contained both formal and informal varieties, the term colloquial was not so effective, because it lacks an antonym apart from non-colloquial, and the like."
• "Although reverting to the colloquial is accepted when one wishes to avoid any confusion as to characterization. datingjesus"
• "Johnson scorned what he called colloquial barbarisms."