Spit out, then apply tongue round — to adjust this? (8)
I believe the answer is:
lipstick
'round to adjust this?' is the definition.
The definition suggests a singular noun which matches the answer.
'spit out then apply tongue' is the wordplay.
I cannot really understand how this works, but
an anagram of 'spit' is 'ipst' which is present in the answer.
'tongue' could be 'lick' and 'lick' is found in the remaining letters.
No letters remain.
This explanation may well be incorrect...
(Other definitions for lipstick that I've seen before include "Type of paint" , "Facial cosmetic" , "Pick list, oddly, for the cosmetic" , "girl may have to face" , "Cosmetic item" .)