Conservative majority vote in 2016 involving a grand split (8)
I believe the answer is:
cleavage
'conservative majority vote in 2016' is the definition.
I can't tell whether this definition defines the answer.
'involving a grand split' is the wordplay.
'involving' indicates putting letters inside.
'grand' becomes 'g' (G is short for grand as in a thousand).
'split' becomes 'cleave' (synonyms).
'a'+'g'='ag'
'ag' put into 'cleave' is 'CLEAVAGE'.
Can you help me to learn more?
(Other definitions for cleavage that I've seen before include "Split (visible when wearing a low-cut dress)" , "bit of a bust-up" , "Hollow shown by low-cut dress" , "Cell division" , "Act of splitting" .)