semi-ˈopen, a.
[semi- 1 a, 8 a.]
Partially open; spec. in Med., applied to methods of administering anæsthetics in which the inspired gas is atmospheric air partially restricted or controlled by some device. Cf. open a. 11 h, semi-closed adj. (b) s.v. semi- 8.
| 1914 J. T. Gwathmey Anesthesia vi. 276 If ethyl chlorid [sic] is administered to adults from an open or semi-open inhaler large quantities of the drug will be needed to bring about even partial anesthesia. 1972 [see open a. 11 h]. |