Medicinal compound men start taking on holiday? (7)
I believe the answer is:
menthol
'medicinal compound' is the definition.
(I've seen this before)
'men start taking on holiday?' is the wordplay.
'start' suggests taking the first letters.
'on' is a charade indicator (letters next to each other).
'holiday?' becomes 'hol' (short for holiday).
The first letter of 'taking' is 't'.
'men'+'t'+'hol'='MENTHOL'
(Other definitions for menthol that I've seen before include "Peppermint oil derivative" , "Chemical compound that smells like mint" , "Minty substance" , "mild analgesic" , "medicinal compound" .)