[Possibly represents ONF. *coque = Fr. coche, It. cocca notch: cf. COCK v., also CAUKING, all referring to the fitting of a projection into a notch, indentation or hollow.]
1. A tabular projection left on the face of a scarfed timber, to fit into a recess in the face of another which is to be joined to it, so as to prevent slipping and make a stronger joint; especially used in the making of masts of several pieces. By the Thames shipbuilders called ‘table,’ the operation being ‘tabling.’ ? Obs.
1794. Rigging & Seamanship, I. 4. Coaks are oblong ridges left on the surface of different pieces of made-masts by cutting away the wood round them; the intermediate part is called the plain…. Cook and plain is when a coak is formed, and a plain surface follows between that and the next. Running coaks are coaks continued the whole length along the middle…. Chain coaks are formed one at the end of the other on the opposite sides of the middle-line.
1867. Smyth, Sailor’s Word-bk., s.v. Coaking, Coaks, or dowels, are fitted into the beams and knees of vessels, to prevent their slipping.
† 2. A turned piece of hard wood received into both timbers for the same purpose as in 1; a dowel. Obs.
c. 1858. Archit. Soc. Dict., C. 107. Coak, a term applied to a wood pin.
1874. Knight, Dict. Mechanics.
3. A small triangular or square piece of brass inserted into the wooden sheave of a block, to afford a stronger socket for the pin. Sometimes more loosely applied to the circular ‘bush’ used with a metal sheave. Also called cock: see COCK sb.1 17.
1862. Totten cited by Webster (1864).
1889. F. Scrutton (in letter), ‘Coak’ as the bush of the sheave of a block, is still a living word on the Thames; it is however old-fashioned, and is being superseded by ‘bush.’
