Wait - there's underwear that is to be put out (6)
I believe the answer is:
linger
This could be a double definition.
'wait there's underwear that' is the first definition.
'linger' can be an answer for 'wait' (thesaurus). I'm not certain of the remainder of the definition.
'be put out' is the second definition.
'linger' can be an answer for 'be' (lingering is a kind of being). I am not sure about the 'put out' bit.
'is to' acts as a link.
Can you help me to learn more?
(Other definitions for linger that I've seen before include "Remain for long" , "Dawdle, hang around" , "Hang about, don't be in a hurry to go" , "'Loiter, delay leaving (6)'" , "Stay on as if reluctant to leave" .)