Existent, a.
Etymology: [L. existens, -entis, p. pr. of existere. See Exist.]
Having being or existence; existing; being; occurring now; taking place. The eyes and mind are fastened on objects which have no real being, as if they were truly existent. Dryden.
Shades of meaning
Fernald has no entry of its own for existent; he lists it under alive.
Where he writes about it:
Alive applies to all degrees of life, from that which shows one to be barely existing or existent as a living thing, as when we say he is just alive, to that which implies the very utmost of vitality and power, as in the words "he is all alive," "thoroughly alive." So the word quick, which began by signifying "having life," is now mostly applied to energy of life as shown in swiftness of action. — from alive