Tease, at least in pants (9)
I believe the answer is:
tantalise
'tease' is the definition.
(I know that tease can be written as tantalise)
'at least in pants' is the wordplay.
'pants' indicates anagramming the letters (UK informal term for 'nonsense' or 'rubbish').
'at'+'least'+'in'='atleastin'
'atleastin' with letters rearranged gives 'TANTALISE'.
(Other definitions for tantalise that I've seen before include "Tease and entice" , "Tease cruelly" , "Tease, torment" .)