teeny weeny adjective tiny US,1931 “Teeny” came from “tiny”, and then the reduplicative “teeny weeny”, which is often found in the same breath as “itsy bitsy”.
“I still don’t feel it,” Mickey said, “the grass. Maybe just a teeny bit.” “A teeny weeny bit?” Louis said. “A teeny-weeny weeny weeny-weeny bit,” Mickey said. — Elmore Leonard, Switch, p. 159, 1978