co ‧ a ‧ lesce /ˌkəʊəˈles $ ˌkoʊ-/ BrE AmE verb [intransitive] formal
[ Date: 1500-1600 ; Language: Latin ; Origin: coalescere , from co- ( ⇨ ↑ co- ) + alescere 'to grow' ]
if objects or ideas coalesce, they combine to form one single group SYN fuse
coalesce into/with
Gradually the different groups of people coalesced into one dominant racial group.
—coalescence noun [uncountable]