Indicated it was sharp (7)
I believe the answer is:
pointed
'indicated' is the definition.
('point' can be a synonym of 'indicate')
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for pointed that I've seen before include "With a tapered tip" , "keen" , "sharpish" , "Of remark, direct and cutting" , "Rudely indicated" .)