Companion's "Phwoar!" occasionally in bed? (6)
I believe the answer is:
cohort
'companion's' is the definition.
(I've seen this before)
'phwoar occasionally in bed?' is the wordplay.
'occasionally' means one should take alternating letters (letters taken at regular intervals or occasions).
'in' means one lot of letters goes inside another.
'bed?' becomes 'cot' (cot is a type of bed).
The alternate letters of 'phwoar' are 'hor'.
'hor' placed inside 'cot' is 'COHORT'.
(Other definitions for cohort that I've seen before include "Warrior band (orig. legion section)" , "Companion or follower" , "Ancient Roman military unit" , "Band of warriors" , "Band of fighters" .)