CLINKER . (a) (From an old Dutch word klinkaerd, from klinken, to

ring), a hard paving brick, a brick with a vitrified surface, or a fused mass of brick; also the incombustible residue of coal, which occurs, half-fused into hard masses, in grates or furnaces; a fused mass of lava . (2) (From clinch, or clench, a common Teutonic word, meaning " to fasten together "), a term appearing usually in the form " clinker-built " as opposed to " cravel-built," for a boat whose stoles overlap and are not fastened .