Pin, n. [OE. pinne, AS.
pinn a pin, peg; cf. D. pin, G. pinne, Icel.
pinni, W. pin, Gael. & Ir. pinne; all fr. L.
pinna a pinnacle, pin, feather, perhaps orig. a different word
from pinna feather. Cf. Fin of a fish, Pen a
feather.] 1. A piece of wood, metal, etc.,
generally cylindrical, used for fastening separate articles together,
or as a support by which one article may be suspended from another; a
peg; a bolt.
With pins of adamant
And chains they made all fast.
Milton.
2. Especially, a small, pointed and headed
piece of brass or other wire (commonly tinned), largely used for
fastening clothes, attaching papers, etc.
3. Hence, a thing of small value; a
trifle.
He . . . did not care a pin for
her.
Spectator.
4. That which resembles a pin in its form or
use; as: (a) A peg in musical instruments,
for increasing or relaxing the tension of the strings.
(b) A linchpin. (c) A
rolling-pin. (d) A clothespin.
(e) (Mach.) A short shaft, sometimes
forming a bolt, a part of which serves as a journal. See
Illust. of Knuckle joint, under Knuckle.
(f) (Joinery) The tenon of a dovetail
joint.
5. One of a row of pegs in the side of an
ancient drinking cup to mark how much each man should drink.
6. The bull's eye, or center, of a target;
hence, the center. [Obs.] "The very pin of his heart
cleft." Shak.
7. Mood; humor. [Obs.] "In merry
pin." Cowper.
8. (Med.) Caligo. See
Caligo. Shak.
9. An ornament, as a brooch or badge, fastened
to the clothing by a pin; as, a Masonic pin.
10. The leg; as, to knock one off his
pins. [Slang]
Banking pin (Horol.), a pin against
which a lever strikes, to limit its motion. -- Pin
drill (Mech.), a drill with a central pin or
projection to enter a hole, for enlarging the hole, or for sinking a
recess for the head of a bolt, etc.; a counterbore. --
Pin grass. (Bot.) See
Alfilaria. -- Pin hole, a small hole
made by a pin; hence, any very small aperture or perforation. --
Pin lock, a lock having a cylindrical bolt; a
lock in which pins, arranged by the key, are used instead of
tumblers. -- Pin money, an allowance of
money, as that made by a husband to his wife, for private and personal
expenditure. -- Pin rail (Naut.), a
rail, usually within the bulwarks, to hold belaying pins. Sometimes
applied to the fife rail. Called also pin rack. --
Pin wheel. (a) A contrate wheel
in which the cogs are cylindrical pins. (b)
(Fireworks) A small coil which revolves on a common pin and
makes a wheel of yellow or colored fire.