[f. TRI- + Gr. βραχίων arm.] A figure or object having three arms or branches; spec. a prehistoric flint implement of this form. So Tribrachial a., having three arms or branches.
1873. A. Way, in Archæol. Jrnl., XXX. 28. The implement … is of a form that may be designated tribrachial, having three branches radiating from the centre. Ibid., 31. The unique tribrachial implement. Ibid. The flint tribrach was presented … by the late Dr. Martin in 1853, with other objects from Ventnor.
1897. Sir J. Evans, Anc. Stone Implem. Gt. Brit., iv. 78. A singular instrument chipped out of flint, like three celts conjoined…, so as to form a sort of tribrach.
