the.com/colloquial
Language wearing pajamas instead of a suit — how people actually talk.
means Describes informal, conversational words and phrases used in everyday speech rather than formal writing.
from From Latin colloquium, a conversation — col- (together) plus loqui (to speak), so literally a speaking-together.
Not slangBroader and longer-lived than fleeting slang.
Dictionary tagOften marked colloq. to flag casual usage.
Same rootShares loqui with eloquent and ventriloquist.