Crossword Genius

Unconventional intellectual, abandoned by university, has cut Charlie off for being a snitch (8)

Ross

I believe the answer is:

telltale

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

'a snitch' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for telltale that I've seen before include "One spreads other people's secrets" , "Person who blabs or something that reveals" , "One revealing secrets" , "Outward indication of something concealed" , "Revealer of secrets" .)

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