||Ple"num, n. (Ventilation) A condition, as in an occupied room, in which the pressure of the air is greater than that of the outside atmosphere; as, a plenum may exist in a hall ventilated by a fan blower.
Plex"us (?), n. A network; an intricate or interwoven combination of elements or parts in a coherent structure.
In the perception of a tree the reference to an object is circumscribed and directed by a plexus of visual and other presentations.
G. F. Stout.
Plop (?), v. i. [imp. & p. p. Plopped (?); p. pr. & vb. n. Plopping.] [Imitative.] To fall, drop, or move in any way, with a sudden splash or slap, as on the surface of water.
The body plopped up, turning on its side.
Kipling.
Plop, n. Act of plopping; the sound made in plopping.
Plout"er (?), v. i. [Also plowter, plotter.] [Perh. imitative.] To wade or move about with splashing; to dabble; also, to potter; trifle; idle. [Scot. & Dial. Eng.]