Sharp comment's signal to pursue end of office party outside (8)
I believe the answer is:
barbecue
'party outside' is the definition.
(party in an outdoor area)
'sharp comment's signal to pursue end of office' is the wordplay.
'sharp comment' becomes 'barb' (a barb is a sharp or hurtful remark).
'signal' becomes 'cue' (I've seen this before).
'to pursue' says to put letters next to each other.
'end of' indicates one should take the final letters.
The final letter of 'office' is 'e'.
'cue' put after 'e' is 'ecue'.
'barb'+'ecue'='BARBECUE'
(Other definitions for barbecue that I've seen before include "Outdoor cookery" , "Meal cooked outside" , "Cuba beer for outdoor meat meal" , "Cook-out" , "grilling" .)