The noun has 2 meanings:
Meaning #1:
an occurrence that results in things being united
Synonym: combine
Meaning #2:
the act of combining things to form a new whole
Synonyms: combination, compounding
The adjective combining has 2 meanings:
Meaning #1:
able to or tending to combine
Synonyms: combinable, combinational, combinatory
Meaning #2:
forming derivative or compound words by putting together constituents each of which expresses a single definite meaning
Synonyms: agglutinative, polysynthetic
