He has it at the conclusion so stop a moment (8)
I believe the answer is:
hesitate
'so stop a moment' is the definition.
I can't tell whether this defines the answer.
'he has it at the conclusion' is the wordplay.
'he has' becomes 'hes' (he's).
'conclusion' suggests the final letters.
The last letter of 'the' is 'e'.
'hes'+'it'+'at'+'e'='HESITATE'
Can you help me to learn more?
(Other definitions for hesitate that I've seen before include "Be reluctant" , "Vacillate" , "Be in two minds" , "Be uncertain about decision" , "Lack confidence" .)