Haste (4)
(Other definitions for despatch that I've seen before include "Give send-off" , "Send out - chest pad (anag)" , "Send off, kill" , "expedition" , "Send out of cash dept" .)
'haste' is the definition.
(I know that haste can be written as rush)
This is all the clue.
(Other definitions for rush that I've seen before include "Move hastily; plant" , "Stampede - water plant" , "Lose no time" , "Hurry to the river grass" , "Deal with (something) hurriedly" .)
'haste' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for urgency that I've seen before include "Haste" , "Need for immediate action" , "Immediate importance" , "Drive, impulse" , "Pressing importance requiring speedy action" .)