Solid figure in pair is married (5)
I believe the answer is:
prism
'solid figure' is the definition.
(I've seen this before)
'pair is married' is the wordplay.
'pair' becomes 'pr'.
'married' becomes 'm'.
'pr'+'is'+'m'='PRISM'
'in' acts as a link.
(Other definitions for prism that I've seen before include "Theatrical Miss" , "Light-splitting object" , "Miss _____, governess in he Importance of Being Earnest"" , "something that colours views?" , "Optical device used to deviate a beam" .)