Crossword Genius

Secret formula in tablet, this one? (7)

Ross

I believe the answer is:

codeine

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

'one?' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.

'secret formula in tablet' is the wordplay.
'secret formula' becomes 'code' (I can't justify this - if you can you should give a lot more credence to this answer).
'tablet' becomes 'e' (E can mean ecstasy or an ecstasy tablet).
'code'+'in'+'e'='CODEINE'

'this' is the link.

Can you help me to learn more?

(Other definitions for codeine that I've seen before include "An anodyne" , "Mild narcotic used as a pain-killer" , "Painkiller derived from opium" , "Niece, do take this drug" , "Analgesic drug" .)

I've seen this clue in The Times.
Want a hint initially instead of a full solution? Install my app