Also 7 trigg. Now dial. and in workmen’s speech. [Goes with TRIG v.2, of obscure origin.] A line traced, cut, or marked out on the ground, as a boundary or center line, a guide for a cutting, etc.; the line or score at which a player at bowls, quoits, curling, etc., stands, or from which runners start in a race; hence to foot or toe the trig; also dial. a shallow trench, gutter, or small ditch, a narrow path or track (Eng. Dial. Dict.).
1648. Davenant, Long Vac. in Lond., 98. Now Alderman in field does stand, With foot on Trig, a Quoit in hand.
1688. R. Holme, Armoury, III. xvi. (Roxb.), 70/1. The Trigg is the place or mark on which the players are to set one foot, or foot the Trigg, when they deliuer their Bowles.
1796. Grose’s Dict. Vulg. T. (ed. 3), Trig, the point at which schoolboys stand to shoot their marbles at taw; also the spot whence bowlers deliver the bowl.
1843. Civil Eng. & Arch. Jrnl., VI. 22/1. He is also … to preserve the centre or trig line, especially in curves.
1893–4. Northumbld. Gloss., Trig, the starting line in a race, which may be either a stretched cord, a stick, a post, or an imaginary boundary.
1895. E. Anglia Gloss., Trig, (2) The mark from which a ball is delivered.
