Business in this spot is to form a unified whole (6)
I believe the answer is:
cohere
'to form a unified whole' is the definition.
(to cohere is to make a unified or cohesive whole)
'business in this spot' is the wordplay.
'business' becomes 'co' (short for company).
'in this spot' becomes 'here' ('here' means in this location).
'co'+'here'='COHERE'
'is' acts as a link.
(Other definitions for cohere that I've seen before include "Hold firmly together" , "Cling" , "Stick firmly together" , "Stick together, remain united" , "Fit together" .)