Rod (?), n. [The same word
as rood. See Rood.]
1. A straight and slender stick; a wand; hence,
any slender bar, as of wood or metal
(applied to various
purposes). Specifically: (a) An instrument of punishment or correction; figuratively, chastisement.
He that spareth his rod hateth his son.
Prov. xiii.
24. (b) A kind of
sceptor, or badge of office; hence, figuratively, power; authority; tyranny; oppression. "The rod, and bird of peace." Shak. (c) A support for a
fishing line; a fish pole. Gay. (d) (Mach. & Structure) A member used in tension, as for sustaining a suspended weight, or in
tension and compression, as for transmitting reciprocating motion, etc.; a connecting bar. (e)
An instrument for measuring.
2. A measure of length containing sixteen and a half feet; -- called also perch, and pole.
Black
rod. See in the Vocabulary. -- Rods and cones (Anat.), the elongated cells or elements of the sensory layer of the retina, some of which are
cylindrical, others somewhat conical.