compact1 (def 7).
concave on both sides, as a lens. Historical Examples The Vertebrate Skeleton Sidney H. Reynolds The Whence and the Whither of Man John Mason Tyler The Vertebrate Skeleton Sidney H. Reynolds Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 3 Various The Works of Francis Maitland Balfour, Volume III (of 4) Francis Maitland Balfour A Guide […]
(of a proposition) asserting that the existence or occurrence of one thing or event depends on, and is dependent on, the existence or occurrence of another, as “A if and only if B.”. noun another name for equivalence (sense 2)
an object shaped like two cones with their bases together.
of, on, or involving two continents: a bicontinental survey.