Black fruit or fruitcake? (7)

I believe the answer is:

bananas

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

'black fruit' is the definition.
'bananas' can be an answer for 'fruit' (I've seen this before). I'm unsure of the 'black' bit.

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for bananas that I've seen before include "Fruit; mad" , "Crazed" , "off 27 [TROLLEY]" , "nutty" , "Mad - curved fruits" .)

I've seen this clue in The Hindu.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.