Holds note, displaying urgency (5)
I believe the answer is:
haste
'urgency' is the definition.
(thesaurus)
'holds note' is the wordplay.
'holds' becomes 'has' ('have' can be a synonym of 'hold').
'note' becomes 'te' (**).
'has'+'te'='HASTE'
'displaying' is the link.
(Other definitions for haste that I've seen before include "Promptitude" , "More of this can slow you up!" , "The more of it, the less speed, it is said" , "Inconsiderate speed" , "More of this proverbially slows you down" .)