Chapter Pennyworth to Pentateuchal of P by Webster's Dictionary (1913 Edition)

Pentacron
(Pen*ta"cron) n.; pl. L. Pentacra E. Pentacrons [NL., fr. Gr. five + a summit.] (Geom.) A solid having five summits or angular points.

Pentacrostic
(Pen`ta*cros"tic) n. [Penta- + acrostic.] A set of verses so disposed that the name forming the subject of the acrostic occurs five times — the whole set of verses being divided into five different parts from top to bottom.

Pentad
(Pen"tad) n. [Gr. a body of five, fr. five.] (Chem.) Any element, atom, or radical, having a valence of five, or which can be combined with, substituted for, or compared with, five atoms of hydrogen or other monad; as, nitrogen is a pentad in the ammonium compounds.

Pentad
(Pen"tad), a. (Chem.) Having the valence of a pentad.

Pentadactyl
(Pen`ta*dac"tyl, Pen`ta*dac"tyle) a. [Gr. with five fingers or toes. See Penta- , and Dactyl.]

1. (Anat.) Having five digits to the hand or foot.

2. Having five appendages resembling fingers or toes.

Pentadactyloid
(Pen`ta*dac"tyl*oid) a. [Pentadactyl + -oid.] (Anat.) Having the form of, or a structure modified from, a pentadactyl limb.

Pentadecane
(Pen`ta*dec"ane) n. [Penta- + Gr. ten.] (Chem.) A hydrocarbon of the paraffin series, (C₁₅H₃₂) found in petroleum, tar oil, etc., and obtained as a colorless liquid; — so called from the fifteen carbon atoms in the molecule.

Pentadecatoic
(Pen`ta*dec`a*to"ic) a. [Penta- + decatoic.] (Chem.) Of, pertaining to, or derived from, pentadecane, or designating an acid related to it.

Pentadecylic
(Pen`ta*decyl"ic) a. [Penta- + decylic.] (Chem.) Same as Quindecylic.

Pentadelphous
(Pen`ta*del"phous) a. [Penta- + Gr. brother.] (Bot.) Having the stamens arranged in five clusters, those of each cluster having their filaments more or less united, as the flowers of the linden.

Pentafid
(Pen"ta*fid) a. [Penta- + root of L. findere to split.] (Bot.) Divided or cleft into five parts.

Pentaglot
(Pen"ta*glot) n. [Penta- + -glot, as in polyglot.] A work in five different tongues.

Pentagon
(Pen"ta*gon) n. [Gr. (see Penta-) + gwni`a angle: cf. L. pentagonium, F. pentagone.] (Geom.) A plane figure having five angles, and, consequently, five sides; any figure having five angles.

Regular pentagon, a pentagon in which the angles are all equal, and the sides all equal.

Pentagonal
(Pen*tag"o*nal) a. [Cf. F. pentagonal, pentagone, L. pentagonus, pentagonius, Gr. .] Having five corners or angles.

Pentagonal dodecahedron. See Dodecahedron, and Pyritohedron.

Pentagonally
(Pen*tag"o*nal*ly), adv. In the form of a pentagon; with five angles. Sir T. Browne.

Pentagonous
(Pen*tag"o*nous) a. Pentagonal.

Pentagram
(Pen"ta*gram) n. [Gr. neut. of having five lines. See Penta-, and -gram.] A pentacle or a pentalpha. "Like a wizard pentagram." Tennyson.