Get a seat when prepared to stand (6)
I believe the answer is:
settee
'get a seat' is the definition.
(I've seen this before)
'prepared to stand' is the wordplay.
'prepared' becomes 'set' (I've seen this before).
'to stand' becomes 'tee' (I've seen this in other clues).
'set'+'tee'='SETTEE'
'when' is the link.
(Other definitions for settee that I've seen before include "Bench" , "Comfy seat" , "Comfy seating" , "Sofa, couch" , "Long indoor seat" .)