pentatonic
adj.
5see PENTA3 & TONIC6designating or of a musical scale having five tones to the octave
Now, there’s a stupid difinition. An octave of five notes?

pentryl - from M-W online, a five part explosive. Same site mentioned “pentadecs = groups of fifteen

Perduellion
(Per`du*el"lion) n. [L. perduellio; per + duellum, bellum, war.] (Civil Law) Treason.
Perdulous
(Per"du*lous) a. [See Perdu, a.] Lost; thrown away. [Obs.] Abp. Bramhall


peregrinate
vt.
3nat#ed, 3nat#ing 5< L peregrinatus, pp. of peregrinari < peregrinus: see PILGRIM6 to follow (a route, etc.); travel, esp. walk, along, over, or through
vi.
to travel
per#e[gri[na4tion
n.
per4e[gri[na#tor
n.
pilgrim I never saw the etymology below before. Worth glancing at.
n.
5ME pelegrim < OFr pelegrin < LL(Ec) pelegrinus < L peregrinus, foreigner < peregre, from abroad < per, through + ager, field, country: see ACRE6
1 a person who travels about; wanderer
2 a person who travels to a shrine or holy place as a religious act
>3 [P3] any member of the band of English Puritans who founded Plymouth Colony in 1620

perfidious
adj.
5L perfidiosus6 characterized by perfidy; treacherous
—SYN FAITHLESS
per[fid$i[ous[ly
adv.
Napoleon called Britain “Perfidious Albion”


perforce f
adv.
5ME par force < OFr: see PER & FORCE6by or through necessity; necessarily


pergamenous - like parchment

periotic
adj.
5PERI3 + 3OTIC6 surrounding the inner ear; specif., of the bone (periotic bone) enclosing the inner ear of mammals

Periapt
(Per"i*apt) n. [Gr. fr. hung about, to hang about; about + to tie: cf. F. périapte.] A charm worn as a protection against disease or mischief; an amulet. Coleridge.
Now help, ye charming spells and periapts.
Shak.

Periclitate
(Pe*ric"li*tate) v. t. [L. periclitatus, p. p. of periclitari, fr. periculum.] To endanger. [Obs.]

Perisarc
<XPAGE=1067Per"i*sarc (?), n. [Pref. peri- + Gr. , , flesh.] (Zoöl.) The outer, hardened integument which covers most hydroids.
Periscian
<XPAGE=1067Pe*ris"cian (?), a. [Gr. ; around + shadow: cf. F. périscien.] Having the shadow moving all around.
Periscians, Periscii
<XPAGE=1067Pe*ris"cians (?), Pe*ris"ci*i (?), n. pl. [NL. See Periscian.] Those who live within a polar circle, whose shadows, during some summer days, will move entirely round, falling toward every point of the compass.

Peristerion
<XPAGE=1067Per`is*te"ri*on (?), n. [NL., fr. Gr. a dovecote, a kind of verbena, fr. a dove, pigeon; cf. L. peristereon.] (Bot.) The herb vervain (Verbena officinalis).