Meeting of two halves is unusually quorate (7)
I believe the answer is:
equator
'meeting of two halves' is the definition.
(where two hemispheres meet)
'unusually quorate' is the wordplay.
'unusually' indicates anagramming the letters.
'quorate' is an anagram of 'EQUATOR'.
'is' acts as a link.
(Other definitions for equator that I've seen before include "Imaginary circle round the earth" , "Imaginary line around the earth's centre" , "Line separating northern and southern hemispheres" , "Imaginary line around the earth's circumference" , "Line of zero latitude" .)