Green’s Dictionary of Slang

1. (orig. US) a diaphragm.

1970

(con. 1950s) H. Junker ‘The Fifties’ in Eisen Age of Rock 2 (1970) 102: Sophisticates referred to her device as a flying saucer.

2. (drugs) the seeds of the plant Ipomoea, popularly known as morning glory.

1969		R.R. Lingeman Drugs from A to Z (1970) 97: Flying Saucers [trade name] A variety of morning glory, the seeds of which have hallucinogenic properties.
1977		L. Young et al. Recreational Drugs.
1981		D.E. Miller Bk of Jargon 337: flying saucers: Morning-glory seeds, an hallucinogen.

3. (N.Z. prison) one capsule of the strong tranquilizer, Largactil.

1982		G. Newbold Big Huey 248: flying saucer (n) Largactil pill.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 72/1: flying saucer n. 1 a largactil pill.

4. (W.I.) a motorcycle police officer.

1951

cited in Cassidy & LePage Dict. Jam. Eng. (1980).

5. (N.Z.) a fried slice of luncheon sausage.

2003

McGill Reed Dict. of N.Z. Sl.