- outdoor (adj.)
[outdoor 词源字典]
- 1748, from out + door. Out-of-door is from c. 1800.[outdoor etymology, outdoor origin, 英语词源]
- outdoors (adv.)
- 1817, from outdoor + adverbial genitive. As a noun, "open spaces," recorded from 1857.
- outdoorsman (n.)
- 1924, American English, from outdoors + man (n.).