skulking animal

江戸川乱歩の短編小説 'Two Crippled Men'を読んでいます。

Still avoiding the other's piercing look, he quietly sneaked out of the room like some skulking animal.

"skulking animal" の "skulking" が分かりません。辞書を見ます。

・Dictionary.com: to move in a stealthy manner; The panther skulked through the bush.
・Collins Dictionary: If you skulk somewhere, you hide or move around quietly because you do not want to be seen.: You, meanwhile, will be skulking in the safety of the car.
・Wordnet 3.0: move stealthily: "The lonely man skulks down the main street all day"

""sculk" とも綴られる様ですが、いずれにせよ余り使われなくなった単語の様です。