For a time, desultorily tries on dresses (7)
I believe the answer is:
attires
'dresses' is the definition.
(attiring is a kind of dressing)
'for a time desultorily tries' is the wordplay.
I cannot quite see how this works, but
'a' is present in the answer.
'time' could be 't' (abbreviation) and 't' is present in the answer.
an anagram of 'tries' is 'tires' which is present in the answer.
No letters remain.
This explanation may well be incorrect...
'on' acts as a link.
Can you help me to learn more?
(Other definitions for attires that I've seen before include "Clothes" , "Dresses" .)