Crossword Genius

Christobel is killed, pierced by a dagger (7)

Ross

I believe the answer is:

obelisk

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

'dagger' is the definition.
(synonyms)

'christobel is killed pierced by a' is the wordplay.
'OBELISK' is hidden in amongst the letters.
But, I'm unsure how the hidden word is indicated.

Can you help me to learn more?

(Other definitions for obelisk that I've seen before include "Kind of monument, tall sloping pillar" , "Stone pillar tapering towards a point" , "Monument with four sides and tapering top" , "Tapering pillar erected as monument" , "Monument with tall pillar and tapering top" .)

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