Drag bundles of corn endlessly (5)
I believe the answer is:
heave
'drag' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for heave that I've seen before include "Pitch" , "Tug-of-war shout" , "Produce (a sigh); retch" , "Throw with force - retch" , "Gasp" .)