No. "Living" is not an accidental but an essential predicate because the name is given from a certain external appearance, namely, self-movement, yet not precisely to signify this, but rather to signify a substance to which self-movement (and the application of itself to any kind of operation) belongs naturally.
"To live", accordingly, is nothing else than to exist in this or that nature. And "living" signifies this, though in the abstract, just as the word "running" denotes "to run" in the abstract.
From external appearances we come to the knowledge of the essence of things. And because we name a thing in accordance with our knowledge of it (Q13, A1), so from external properties names are often imposed to signify essences.
Hence such names are sometimes taken strictly to denote the essence itself, the signification of which is their principal object; but sometimes, and less strictly, such names are taken to denote the properties by reason of which such names are imposed.