1949 4 Sept. 5/3 A butterfly tail gives the jet efflux a free run.
1966 D. Stinton 244 The position of the fin was an initial argument against mounting the engine above the boom, because of the hot jet efflux playing on the surfaces.
2005 (Nexis) 11 Nov. (Columns section) 11 Their jet efflux is heavier than air; it drifts downwards.