To fall into mistake, fault, or error; to err, †to sin. Also with into (error, etc.).

figurative in various uses. To make a slip in speech or action; to blunder through inadvertence or unpreparedness.

intransitive. To make use of, or commit, solecisms in language, behaviour, conduct, etc.

intransitive. To speak or write like a barbarian; to violate the laws of Latin or Greek grammar.