plural of Bornean swiftlet

Any of various small passerine birds from the family Sittidae found throughout the Northern hemisphere that have the unusual ability to climb down trees head first.

(humorous) Said when asked the time, humorously indicating that one does not know or does not care to check, or that one is not wearing a wristwatch and that nothing is to be seen on the wrist but ...

(organic chemistry) Initialism of polyacrylic acid.