Is it true that is the word ain't in the english dictionary based on the following text?

Ain't as a contraction for has not/have not first appeared in dictionaries in the 1830s, and appeared in 1819 in Niles' Weekly Register: Strike! Why I ain't got nobody here to strike... Charles Dickens likewise used ain't to mean haven't in Chapter 28 of Martin Chuzzlewit (1844): ''You ain't got nothing to cry for, bless you! He's righter than a trivet!''
yes