- 1of, on, or facing the outer side synonym external The outside walls are damp.
- 2not located in the main building; going out of the main building synonym external an outside toilet You have to pay to make outside calls. I can't get an outside line.
- 3not included in or connected with your group, organization, country, etc. We plan to use an outside firm of consultants. She has a lot of outside interests (= not connected with her work). They felt cut off from the outside world (= from other people and from other things that were happening).
- 4used to say that something is very unlikely They have only an outside chance of winning. 150 is an outside estimate (= it is very likely to be less).
NAmE//ˈaʊtsaɪd//[only before noun]