type of duck, 1767, from pin (n.) + tail (n.); so called from the peculiarity of the tail (narrow with long central feathers). In Middle English it is given once (c. 1300) as an epithet for the hare.
Entries linking to pintail
pin n.
late Old English pinn "peg or bolt of wood or metal used to hold things in place or fasten them together," from Proto-Germanic *penn- "jutting point or peak" (source also of Old Saxon pin "peg," Old Norse pinni "peg, tack," Middle Dutch pin "pin, peg," Old High German pfinn, German Pinne "pin, tack") from Latin pinna "a feather, plume;" in plural "a wing;" also "fin, scoop of a water wheel;" also "a pinnacle; a promontory, cape; battlement" (as in Luke iv.9 in Vulgate) and so applied to "points" of various sorts, from PIE root *pet- "to rush, to fly."
De Vaan and Watkins say Latin pinna is a derivative of penna, literally "feather" (see pen (n.1)); older theories regarded pinna as a separate word from a root meaning "sharp point." The Latin word also was borrowed in Celtic: Irish pinne "a pin, peg, spigot;" Welsh pin "a pin, pen."
The transition from 'feather' to 'pin' (a slender or pointed instrument) appears to have been through 'pen,' a quill, to ' pen,' a style or stylus, hence any slender or pointed instrument [Century Dictionary]
As a part of a lock or latch, c. 1200; as a control for a mechanical device, late 14c. The modern slender wire pin, used as a fastener for clothing or in sewing, is attested by this name by late 14c., perhaps late 13c. Transferred sense of "leg" is recorded from 1520s and holds the older sense. The meaning "wooden stick or club set up to be knocked down in a game" (skittles, bowling, etc.) is by 1570s.
Pin-money "annual sum allotted to a woman for personal expenses on dress, etc." is attested from 1620s. Pins and needles "tingling sensation" is from 1810. The sound of a pin dropping as a type of something all but silent is from 1775.
tail n.1
"hindmost part of an animal," Old English tægl, tægel "a tail," from Proto-Germanic *tagla- (source also of Old High German zagal, German Zagel "tail," dialectal German Zagel "penis," Old Norse tagl "horse's tail," Gothic tagl "hair"), from PIE *doklos, from suffixed form of root *dek- (2) "something long and thin" (referring to such things as fringe, lock of hair, horsetail; source also of Old Irish dual "lock of hair," Sanskrit dasah "fringe, wick").
According to OED, the primary sense, at least in Germanic, seems to have been "hairy tail," or just "tuft of hair," but already in Old English the word was applied to the hairless "tails" of worms, bees, etc. But Buck writes that the common notion is of "long, slender shape." As an adjective from 1670s.
Meaning "reverse side of a coin" (opposite the side with the head) is from 1680s; that of "backside of a person, buttocks" is recorded from c. 1300; slang sense of "pudenda" is from mid-14c.; that of "woman as sex object" is from 1933, earlier "act of copulation" with a prostitute (1846). Of descending strokes of letters, from 1590s.
Tails "coat with tails" is from 1857. The tail-race (1776) is the part of a mill race below the wheel. To turn tail "take flight" (1580s) originally was a term in falconry. The image of the tail wagging the dog is attested from 1907. Another Old English word for "tail" was steort (see stark).