Wordnet 3.0
ADJECTIVE (2)
1. 
 located, suited for, or taking place within a building; 
- Example: "indoor activities for a rainy day"- Example: "an indoor pool"2. 
 within doors; 
- Example: "an indoor setting"
The Collaborative International Dictionary of English v.0.48:
Indoor \In"door`\, a.
   Done or being within doors; within a house or institution;
   domestic; as, indoor work.
   [1913 Webster]
WordNet (r) 3.0 (2006):
indoor
    adj 1: located, suited for, or taking place within a building;
           "indoor activities for a rainy day"; "an indoor pool"
           [ant: out-of-door, outdoor(a), outside]
    2: within doors; "an indoor setting"