Etymology
Advertisement
perch (n.1)

"rod or pole on which a bird alights and rests," late 13c., originally only "a pole, rod, stick, stake," from Old French perche "unit of linear measurement" (5.5 yards), also "measuring rod, pole, bar" used to measure this length (13c.), from Latin pertica "pole, long staff, measuring rod," which is related to Oscan perek "pole," Umbrian perkaf "twigs, rods." Meaning "a bar fixed horizontally for a hawk or tame bird to rest on" is attested from late 14c.; this led to the general sense of "any thing that any bird alights or rests on" (late 15c.). Figurative sense of "an elevated or secure position" is recorded from 1520s.

Related entries & more 
Advertisement
perch (n.2)

common spiny-finned freshwater fish, c. 1300, perche, from Old French perche, from Latin perca "perch," from Greek perkē "a perch," from perknos "spotted, having dark spots," from PIE root *perk- "speckled, spotted" (source also of Sanskrit prsnih "speckled, variegated;" Greek perkazein "to become dark"), typically in names of animals; compare Middle Irish erc, Welsh erch "spotted, dark red; salmon, trout," also "cow, lizard;" Old High German forhana, Old English forne "trout."

Related entries & more 
perch (v.)

"to roost, to alight or settle on or as on a perch; to occupy some elevated position," late 14c., from Old French perchier "to sit on a perch" (of a bird), from perche (n.); see perch (n.1). Related: Perched; perching.

Related entries & more 
perch (n.3)

"measure of land equal to a square lineal perch" (usually 160 to the acre), late 14c., earlier "land-measuring rod" (c. 1300), from Old French perche "unit of linear measurement" (5.5 yards), also "measuring rod, pole, bar" used to measure this length (13c.), from Latin pertica "pole, long staff, measuring rod," which is related to Oscan perek "pole," Umbrian perkaf "twigs, rods." The same word as perch (n.1).

Related entries & more 
perk (n.1)

"horizontal bar serving as a support for various purposes," late 14c., "rod, pole, perch for a hawk," a variant of perch (n.1) or from Medieval Latin perca, Old French perce, variant of perche.

Related entries & more 
Advertisement
perk (v.)

late 14c., perken, "to make oneself trim or smart," perhaps literally "to perch on a tree," from Old North French perquer "to perch" (Modern French percher; see perch (n.1), and compare perk (n.1)), on notion of a bird preening its plumage. Sense of "raise briskly, hold up smartly" is attested from 1520s; perk up "recover liveliness" is from 1650s. Related: Perked; perking.

Þe popeiayes perken and pruynen for proude On peren and pynappel.
["Susannah," Scottish alliterative poem, c. 1390]
Related entries & more 
walleye (n.)
type of fish (pike-perch), 1876, American English, said to be so-called from the positioning of the eyes (see wall-eyed).
Related entries & more 
torii (n.)
singular and plural, "gateway to a Shinto temple," Japanese, according to OED from tori "bird" + i "to sit, to perch."
Related entries & more 
bass (n.1)
freshwater fish, c. 1400 corruption of Middle English baers, from Old English bærs "a fish, perch," from Proto-Germanic base *bars- "sharp" (source also of Middle Dutch baerse, Middle High German bars, German Barsch "perch," German barsch "rough"), from PIE root *bhar- "point, bristle" (see bristle (n.)). The fish was so called for its dorsal fins. For loss of -r-, see ass (n.2).
Related entries & more 
roost (n.)

Middle English roste, "a chicken's perch," from late Old English hrost "wooden framework of a roof; pole or perch upon which domestic fowl perch or rest for the night," from Proto-Germanic *hro(d)-st- (source also of Old Saxon hrost "framework of a roof, attic," Middle Dutch, Flemish, Dutch roest "roost," Old Norse hrot, Gothic hrot "roof"), a word of unknown origin. Extended sense "hen-house" is from 1580s; that of "fowls which occupy the roost collectively" is by 1827.

To rule the roost is recorded from 1769, according to OED apparently an alteration of earlier rule the roast "be the master, have authority " (c. 1500), which, OED reports, was "In very common use from c 1530 onwards." However, Fowler (1926) has doubts: "most unliterary persons say roost & not roast ; I have just inquired of three such, & been informed that they never heard of rule the roast, & that the reference is to a cock keeping his hens in order. Against this tempting piece of popular etymology the OED offers us nothing more succulent than "None of the early examples throw any light on the precise origin of the expression'." The spelling in the earliest example is reule the roste.

Related entries & more