peri-prefix

Etymology: < ancient Greek περι-, combining form of περί , preposition and adverb, ‘round, around, round about, about’ < a different ablaut grade of the Indo-European base of fore prep., combined in these senses with verbs and their derivatives, nouns, and adjectives: (a) in adverbial construction, as περιβλέπειν to look around, περιστρέϕειν to turn round, περίοδος action or act of going round, περίπατος act of walking about, περίχρυσος gilded all over; from the sense ‘all over’, the sense was extended to those of ‘altogether, quite, very, exceedingly, beyond measure’, as in περικαλλής very beautiful, and that of ‘going beyond’ or ‘exceeding’, as in περιτοξεύειν to overshoot; (b) in prepositional construction, forming parasynthetic adjectives and derived nouns, e.g. περικάρδιος ‘situated περὶ καρδίᾳ, around or about the heart’, thence τὸ περικάρδιον ‘the membrane surrounding the heart, the pericardium’.A small number of technical Greek words in περι- were adopted in classical Latin; more were added in post-classical Latin; most of these are represented in the modern Romance languages, and in English (see pericardium n., pericarp n., period n., peripatetic adj., periphery n., periphrase n., periplus n., peristyle n., peritoneum n.); and, on the model of these, adaptations of ancient Greek compounds in περι- , and new compounds from Greek elements (frequently also from Latin elements), have been introduced in great numbers in scientific Latin (especially in biological nomenclature), and in the scientific terminology of the modern languages generally, in which peri- has been found to be a convenient prefix for designating the structure or region lying round a defined organ or part. Most of these terms are (with the appropriate modification of form) of international currency, and it is often difficult to ascertain in which of several languages a particular term was first used. Apparently attested earliest at the end of the 14th cent. in the French and Latin loan periphery n., subsequently in (often medical) loanwords from Latin and French in the 15th cent., all ultimately of Greek origin. Formations within English are found sporadically from the late 16th cent. (see perimetry n., periophthalmium n. at sense 2b, and peridesmium n. at sense 2b); they become increasingly common from the first half of the 19th cent. In sense 1 after perigeum n. Compare French péri- (formations in which are found from the mid 18th cent., apparently earliest in périanthe perianth n.), German peri- (formations in which are found from at least the first half of the 19th cent.). In sense 3a after French péri-hexaèdre , péri-octaèdre , péri-décaèdre , péri-dodécaèdre (R. J. Haüy Traité de minéral. (1801) 185), péri-polygone (R. J. Haüy Traité de minéral. (1801) 190). In sense 3b after French périorthogone (1823 or earlier in Haüy); R. G. Mayne also gives a Latin form periorthogonus (see quot. 1857 for periorthogonous adj. at sense 3b).