Note the least bit of hesitation is absent (5)
I believe the answer is:
minim
'note' is the definition.
(minim is a kind of note)
'the least bit of hesitation is absent' is the wordplay.
'the least' becomes 'minimum' (I've seen this before).
'bit of hesitation' becomes 'um' (expression of hesitation).
'is absent' suggests deleting specific letters.
'minimum' with 'um' taken out is 'MINIM'.
(Other definitions for minim that I've seen before include "It's a downward stroke" , "Note equal to two crochets" , "Half-semibreve" , "Quarter of a breve" , "A note in music, half as long as a semi-breve- it's a palindrome" .)