COEXISTING
coexistent, coexisting
(adjective) existing at the same time
Source: WordNet® 3.1
Verb
coexisting
present participle of coexist
Source: Wiktionary
Co`ex*ist"ing, a.
Definition: Coexistent. Locke.
COEXIST
Co`ex*ist, v. i. [imp. & p. p. Coexisted; p. pr. & vb. n.
Coexisting.]
Definition: To exist at the same time; -- sometimes followed by with.
Of substances no one has any clear idea, farther than of certain
simple ideas coexisting together. Locke.
So much purity and integrity . . . coexisting with so much decay and
so many infirmities. Warburton.
Source: Webster’s Unabridged Dictionary 1913 Edition