Casually mention drop of tanning lotion (8)
I believe the answer is:
ointment
'lotion' is the definition.
(thesaurus)
'casually mention drop of tanning' is the wordplay.
'casually' is an anagram indicator (I've seen this in other clues).
'drop of' indicates taking the first letters.
The first letter of 'tanning' is 't'.
'mention' with letters rearranged gives 'ointmen'.
'ointmen'+'t'='OINTMENT'
(Other definitions for ointment that I've seen before include "Medicinal rub" , "Balm, healing salve" , "Healing or cosmetic preparation" , "Unguent, rub" , "Medicated oily compound" .)