Found 2 items, similar to plumb rule.
English → English (WordNet) Definition: plumb rule plumb rule n : a plumb line attached to a narrow board
English → English (gcide) Definition: Plumb rule Plumb \Plumb\ (pl[u^]m), n. [F. plomb, L. plumbum lead, a leaden ball or bullet; cf. Gr. mo`lybos, mo`libos, mo`lybdos. Cf. Plummet, Plunge.] A little mass or weight of lead, or the like, attached to a line, and used by builders, etc., to indicate a vertical direction; a plummet; a plumb bob. See Plumb line, below. [1913 Webster] Plumb bob. See Bob, 4. Plumb joint, in sheet-metal work, a lap joint, fastened by solder. Plumb level. See under Level. Plumb line. (a) The cord by which a plumb bob is suspended; a plummet. (b) A line directed to the center of gravity of the earth. Plumb rule, a narrow board with a plumb line, used by builders and carpenters. [1913 Webster]