nave-line
/ˈneɪvlʌɪn/Nautical. Now rare (chiefly historical )
noun
In square-rigged sailing vessels: a short line holding the parrel or truss of a yard to the mast or crosstrees, allowing freedom of movement for bracing.
Origin
Early 18th century; earliest use found in William Sutherland (fl. 1711–1717). Probably a variant of knave-line, or perhaps from nave + line, or perhaps from navel + line.