Little songbird (4)
I believe the answer is:
wren
'little songbird' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for wren that I've seen before include "Tiny brown songbird with a short upright tail" , "17th Century architect" , "held up by wings at small scale?" , "serving girl" , "Man of note" .)