COINCIDING
coincident, coincidental, coinciding, concurrent, co-occurrent, cooccurring, simultaneous
(adjective) occurring or operating at the same time; “a series of coincident events”
Source: WordNet® 3.1
Verb
coinciding
present participle of coincide
Noun
coinciding (plural coincidings)
Act or situation by which things coincide; coincidence.
Source: Wiktionary
COINCIDE
Co`in*cide", v. i. [imp. & p. p. Coincided; p. pr. & vb. n.
Coinciding.] Etym: [L. co- + incidere to fall on; in + cadere to
fall: cf. F. coïncider. See Chance, n.]
1. To occupy the same place in space, as two equal triangles, when
placed one on the other.
If the equator and the ecliptic had coincided, it would have rendered
the annual revoluton of the earth useless. Cheyne.
2. To occur at the same time; to be contemporaneous; as, the fall of
Granada coincided with the discovery of America.
3. To correspond exactly; to agree; to concur; as, our aims coincide.
The rules of right jugdment and of good ratiocination often coincide
with each other. Watts.
Source: Webster’s Unabridged Dictionary 1913 Edition