Longed to join soldiers on top, got there (5)

I believe the answer is:

ached

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

'longed' is the definition.
('ache' can be a synonym of 'long')

I don't understand the rest of the clue.

(Other definitions for ached that I've seen before include "Throbbed" , "suffered" , "Felt a dull pain" , "Did long" , "Yearned" .)

I've seen this clue in The Hindu.

Want a hint initially instead of a full solution? Install my app