Fend off with endless fear to overwhelm (6)
I believe the answer is:
deafen
'overwhelm' is the definition.
Although both the answer and definition are verbs in their base form, I can't understand how they can define each other.
'fend off with endless fear' is the wordplay.
'off with' indicates anagramming the letters.
'endless' means to look at the middle letters.
The middle of 'fear' is 'ea'.
'fend' mixed up with 'ea' can make 'DEAFEN'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for deafen that I've seen before include "Cause to lose sense of hearing" , "Cause to lose the power of hearing" , "Cause loss of hearing to (someone)" , "Render senseless" , "Make unable to hear" .)