Strong's 5225 (ὑπάρχω)

after, behave, live

to begin under (quietly), i.e. come into existence (be present or at hand); expletively, to exist (as copula or subordinate to an adjective, participle, adverb or preposition, or as an auxiliary to a principal (verb)

from G5259 (ὑπό) and G756 (ἄρχομαι);