Used to be stood up after dance? It's a puzzle
I believe the answer is:
jigsaw
'a puzzle' is the definition.
(I've seen this before)
'used to be stood up after dance?' is the wordplay.
'used to be' becomes 'was' (ie used to be or was in the past).
'stood up' says the letters should be written in reverse (in a down clue, letters go up).
'after' is a charade indicator (letters next to each other).
'dance?' becomes 'jig' (jigging is a kind of dancing).
'was' back-to-front is 'saw'.
'saw' after 'jig' is 'JIGSAW'.
'it's' is the link.
(Other definitions for jigsaw that I've seen before include "Puzzle - powered cutter" , "Puzzle in which pieces must be reassembled" , "Type of puzzle" , "Picture in pieces" , "As pastime" .)