Left omen out – that’s sharp (5)
I believe the answer is:
lemon
This clue could be a double definition.
'left omen out' is the first definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'that's sharp' is the second definition.
I can't tell whether this defines the answer.
Can you help me to learn more?
(Other definitions for lemon that I've seen before include "leaving bitter taste?" , "Melon (anag)" , "Melon is another fruit" , "Useless object" , "Fruit high in vitamin C" .)