out-of-doors adjective 1adverb 1noun 1out of doors prepositional phrase 1forms 2 adjective1 •Primarily in the open rather than under the cover of habitation. adverb1 •outdoors; outside.Besides the jar of contrast there came to her a chill self-reproach that she had not returned sooner, to help her mother in these domesticities, instead of indulging herself out-of-doors. — 1891 noun1 •outdoors out of doors prepositional phrase1 •Dated form of outdoors (“not inside any building”).You are allowed to smoke out of doors.The cat was out of doors, seemingly enjoying the sun. formsmore out-of-doors · most out-of-doors