It's a lot more than little, note (5)
I believe the answer is:
minim
'note' is the definition.
(minim is a kind of note)
'it's a lot more than little' is the wordplay.
'it's a lot' becomes 'm'.
'more than' means one lot of letters go next to another.
'little' becomes 'mini'.
'm' put after 'mini' is 'MINIM'.
(Other definitions for minim that I've seen before include "Note with value of half a semibreve" , "Two crotchets in one" , "Palindromic note" , "Musical note - small amount of liquid" , "Half-semibreve" .)