Etymology
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perforation (n.)

early 15c., perforacioun, "hole made through something;" mid-15c., "action of boring or piercing," from Medieval Latin perforationem (nominative perforatio), noun of action from past participle stem of Latin perforare "bore or pierce through," from per "through" (from PIE root *per- (1) "forward," hence "through") + forare "to pierce" (from PIE root *bhorh- "hole").

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pertinacity (n.)

"resolute or unyielding adherence," c. 1500, from French pertinacité (early 15c.), from Old French pertinace "obstinate, stubborn," from Latin pertinacem (nominative pertinax) "very firm, tenacious, steadfast, persevering," from per "very" (see per) + tenax (see tenacious). It drove out earlier pertinacy (late 14c.), which was especially "persevering in disbelief."

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perforate (v.)

"bore through, pierce, make a hole or holes in," late 15c. (implied in perforated), a back-formation from perforation or else from Latin perforatus, past participle of perforare "to bore through, pierce through," from per "through" (from PIE root *per- (1) "forward," hence "through") + forare "to pierce" (from PIE root *bhorh- "hole"). Related: Perforating.

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sober (adj.)
mid-14c., "moderate in desires or actions, temperate, restrained," especially "abstaining from strong drink," also "calm, quiet, not overcome by emotion," from Old French sobre "decent; sober" (12c.), from Latin sobrius "not drunk, temperate, moderate, sensible," from a variant of se- "without" (see se-) + ebrius "drunk," of unknown origin. Meaning "not drunk at the moment" is from late 14c.; also "appropriately solemn, serious, not giddy." Related: Soberly; soberness. Sobersides "sedate, serious-minded person" is recorded from 1705.
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seasick (adj.)

also sea-sick, "affected with nausea from the motion of a vessel," 1560s, from sea + sick (n.). Related: Seasickness. Middle English se-sik meant "weary of travelling on the sea" (mid-15c.).

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persiflage (n.)

"light, flippant banter; an ironical or frivolous treatment of a subject," 1757, from French persiflage, from persifler "to banter" (18c.), from Latin per "through" (from PIE root *per- (1) "forward," hence "through") + French siffler "to whistle, hiss," from collateral form of Latin sibilare "to hiss," which possibly is of imitative origin. Said to have been introduced in English by Chesterfield.

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perturb (v.)

late 14c., perturben, "disturb greatly, disturb mentally; cause disorder in," from Old French perturber "disturb, confuse" (14c.) and directly from Latin perturbare "to confuse, disorder, disturb," especially of states of the mind, from per "through" (from PIE root *per- (1) "forward," hence "through") + turbare "disturb, confuse," from turba "turmoil, crowd" (see turbid). Related: Perturbed; perturbing.

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poundage (n.)

early 15c., "tax or subsidy per pound of weight;" 1903 as "weight;" from pound (n.1) + -age.

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pervious (adj.)

"capable of being penetrated or permeated by something else, accessible, permeable," 1610s, originally figurative (literal sense is from 1630s), from Latin pervius "that may be passed through," from per "through" (from PIE root *per- (1) "forward," hence "through") + via "road" (see via (adv.)). Related: Perviousness.

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impervious (adj.)
1640s, from Latin impervius "not to be traverse, that cannot be passed through, impassible," from assimilated form of in- "not, opposite of" (see in- (1)) + pervius "letting things through, that can be passed through," from per "through" (from PIE root *per- (1) "forward," hence "through") + via "road" (see via (adv.)). Related: Imperviously; imperviousness.
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