Having a more momentous relationship? (6)
I believe the answer is:
bigger
'having a more' is the definition.
I can't judge whether this definition defines the answer.
'momentous relationship?' is the wordplay.
'momentous' becomes 'big' (synonyms).
'relationship?' becomes 'ger' (I can't explain this - if you can you should believe this answer much more).
'big'+'ger'='BIGGER'
Can you help me to learn more?
(Other definitions for bigger that I've seen before include "louder" , "Greater in size" , "Larger" , "Comparatively huge" .)