tricyclic, a. (n.)
(traɪˈsɪklɪk, -ˈsaɪklɪk)
[f. Gr. τρι- tri- + κύκλος circle + -ic.]
1. Bot. Arranged in three whorls.
| 1900 in B. D. Jackson Gloss. Bot. Terms. |
2. Chem. a. Of a carbon compound: Having three rings or closed chains of atoms in its structural formula; e.g. phenanthrene. (Ger. tricyklisch.)
| 1891 Jrnl. Chem. Soc. LX. 1258 The two best known tricyclic compounds, anthracene and phenanthrene. |
b. spec. in Pharm., designating or pertaining to a group of antidepressant drugs based upon a molecular structure of three fused rings; also as n.
| 1966 Internat. Jrnl. Neuropharmacol. V. 299 (heading) Association between biochemical and behavioral actions of tricyclic antidepressants. 1972 Daily Tel. 4 Mar. 32/3 He said pregnant women should steer clear of all drugs if possible, particularly drugs known as tricyclic anti⁓depressants. 1973 Sci. Amer. Sept. 121/2 The chemical structures of these two classes of antidepressants—the monamine oxidase inhibitors and the tricyclics—are quite different. 1980 J. Wainwright Man of Law i. 18, I suggested..a good tricyclic antidepressant. |