1. union, combination, coalescence, amalgamation, merger, incorporation

transitive verb intransitive verb noun or participle which takes the aux. verb suru noun (common) (futsuumeishi)

2. conjugation (of gametes)

noun or participle which takes the aux. verb suru noun (common) (futsuumeishi) intransitive verb biology

3. sexual intercourse, copulation

noun or participle which takes the aux. verb suru intransitive verb noun (common) (futsuumeishi) euphemistic