a. Min. [f. as prec. + -OSE.] Of, pertaining to, or of the nature of trap or trap-rock; trappean. Also Trappous a. (rare–0).
1796. Kirwan, Elem. Min. (ed. 2), II. 175. Argillaceous Iron Stone…. Of this sort also we may reckon the *Trappose Ore used … in Sweden. Ibid. (1799), Geol. Ess., 272. The black trappose matter that descends from the summit of the mountain to a torrent at its foot where it forms pillars.
1845. G. H. Smith, in Encycl. Metrop., XXIII. 733/2. From Thunder Mountain, Westward, trappose-greenstone is the prevailing rock.
1828. Webster, *Trappous.
