Definition
Alternative spelling of teensy-weensy.
How People Actually Use It
(adjective) For the last 40 years or so, a term that means something small, tiny. Can be used together with the word itsy-bitsy (see for example the song "Itsy-bitsy teeny-weeny yellow polka-dot bikini").
"Did you see that teeny-weeny skirt on her?"
Source: Urban Dictionary