Long throw needing power (4)

I believe the answer is:

itch

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

'long' is the definition.
(to long or itch for something is to desire it)

I don't understand the rest of the clue.

(Other definitions for itch that I've seen before include "Long" , "A nagging desire" , "Niggling skin sensation" , "Burning" , "Impatient desire (colloq.)" .)

I've seen this clue in The Independent.

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.