英语词源字典 - 在线词源网站

perilous (adj.)[perilous 词源字典]: c. 1300, from Old French perillos "perilous, dangerous" (Modern French périlleux) "dangerous, hazardous," from Latin periculosus "dangerous, hazardous," from periculum "a danger, attempt, risk" (see peril). Related: Perilously; perilousness.[perilous etymology, perilous origin, 英语词源]
perimeter (n.): early 15c., "line around a figure or surface," from Latin perimetros, from Greek perimetron "circumference," from peri- "around" (see peri-) + metron "measure" (see meter (n.2)). Military sense of "boundary of a defended position" is attested from 1943.
perinatal (adj.): 1952, from peri- + natal.
perineum (n.): "region of the body between the anus and the genital organs" (jocularly called a taint), early 15c., from Medieval Latin perinaeon, Late Latin perineum, from Greek perinaion, perinaios, from peri- "near" (see peri-) + inan "to carry off by evacuation," of unknown origin.
period (n.): early 15c., "course or extent of time," from Middle French periode (14c.) and directly from Medieval Latin periodus "recurring portion, cycle," from Latin periodus "a complete sentence," also "cycle of the Greek games," from Greek periodos "cycle, circuit, period of time," literally "a going around," from peri- "around" (see peri-) + hodos "a going, way, journey" (see cede).

Sense of "repeated cycle of events" led to that of "interval of time." Meaning "dot marking end of a sentence" first recorded c. 1600, from similar use in Medieval Latin (in late 16c. English it meant "full pause at the end of a sentence"). Sense of "menstruation" dates from 1822. Educational sense of "portion of time set apart for a lesson" is from 1876. Sporting sense attested from 1898. As an adjective from 1905; period piece attested from 1911.
periodic (adj.): 1640s, from French périodique (14c.), from Latin periodicus, from periodus (see period).

Periodic table in chemistry (1889) is from notion of the arrangement, in which similar properties recur at intervals in elements in the same area as you read down the rows of the table. This sense of the word is attested from 1872 (periodic law).
periodical (adj.): c. 1600, from periodic + -al (1). As a noun meaning "magazine published at regular intervals," attested from 1798. Related: Periodically.
periodicity (n.): 1805, from French périodicité (1796), from périodique, from Latin periodicus (see periodic).
periodontal (adj.): 1848, literally "around the tooth," from peri- + Greek odon (genitive odontos) "tooth" (see tooth).
periodontics (n.): 1948, from periodontia (1914; see periodontal) + -ics. Periodontic (adj.) is attested by 1889.
periodontist (n.): 1913; see periodontal + -ist.
periodontitis (n.): 1842; see periodontal + -itis "inflammation."
periodontium (n.): 1828; see periodontal.
periorbital (adj.): 1838, from medical Latin periorbita, a hybrid from Greek peri (see peri-) + Latin orbita (see orbit).
periosteum (n.): 1590s, from Modern Latin periosteum, Late Latin periosteon, from Greek periosteon, neuter of periosteos "round the bones," from peri- (see peri-) + osteon (see osseous).
peripatetic (n.): c. 1400, "disciple of Aristotle," from Old French perypatetique (14c.), from Latin peripateticus "pertaining to the disciples or philosophy of Aristotle," from Greek peripatetikos "given to walking about" (especially while teaching), from peripatein "walk up and down, walk about," from peri- "around" (see peri-) + patein "to walk, tread" (see find (v.)). Aristotle's custom was to teach while strolling through the Lyceum in Athens. In English, the philosophical meaning is older than that of "person who wanders about" (1610s).
peripatetic (adj.): 1560s in the philosophical sense, 1640s in the literal sense; see peripatetic (n.).
peripeteia (n.): also peripetia, 1590s, from Greek peripeteia "a turn right about; a sudden change" (of fortune, in a tragedy), from peri- "around" (see peri-) + stem of piptein "to fall" (see symptom).
peripheral (adj.): 1803, from periphery + -al (1). An earlier formation was peripherial (1670s). Related: Peripherally. As a noun, peripherals, "peripheral devices of a computer," is from 1966.
periphery (n.): late 14c., "atmosphere around the earth," from Old French periferie (Modern French périphérie), from Medieval Latin periferia, from Late Latin peripheria, from Greek peripheria "circumference, outer surface, line round a circular body," literally "a carrying around," from peripheres "rounded, moving round, revolving," peripherein "carry or move round," from peri- "round about" (see peri-) + pherein "to carry" (see infer). Meaning "outside boundary of a surface" attested in English from 1570s; general sense of "boundary" is from 1660s.