Make harder to fathom? (6)
I believe the answer is:
deepen
This clue might be a double definition.
'make harder' is the first definition.
The definition and answer can be both related to change as well as being verbs in their base form.
Perhaps there's an association between them I don't understand?
'fathom?' is the second definition.
The definition and answer can be both related to change as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?
'to' acts as a link.
Can you help me to learn more?
(Other definitions for deepen that I've seen before include "Make or become more profound" , "Increase in depth" , "To grow" , "make room for more water" , "Make (colour) darker" .)