Crossword Genius

Medicinal substance left by your medical officer (6)

Ross

I believe the answer is:

thymol

I'm a little stuck... Click here to teach me more about this clue!

'medicinal substance' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.

'left by your medical officer' is the wordplay.
'left' becomes 'l' (common abbreviation).
'by' is a charade indicator (letters next to each other).
'your' becomes 'thy' (I've seen this before).
'medical officer' becomes 'mo' (this could be a standard abbreviation of which I'm unaware).
'thy'+'mo'='thymo'
'l' after 'thymo' is 'THYMOL'.

Can you help me to learn more?

(Another definition for thymol that I've seen is " chemical antiseptic".)

Want a hint initially instead of a full solution? Install my app