Wiktionary
thass
vb. (context eye dialect or representing slurred, drunken speech English) (l en that's that’s)
Usage examples of "thass".
U ½ 2 b abil 2 use whotevir is aroun u, & thass whot it reely cums doun 2.
P'alit here claims you attacked him last night behind the Thasser Eya Bar in Farnesee.