From The Collaborative International Dictionary of English v.0.48:
Plump \Plump\, n. A knot; a cluster; a group; a crowd; a flock; as, a plump of trees, fowls, or spears. [Obs.] [1913 Webster]
To visit islands and the plumps of men. --Chapman. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Plump \Plump\, v. i. [Cf. D. plompen, G. plumpen, Sw. plumpa, Dan. plumpe. See Plump, a.] 1. To grow plump; to swell out; as, her cheeks have plumped. [1913 Webster]
2. To drop or fall suddenly or heavily, all at once."Dulcissa plumps into a chair." --Spectator. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Plump \Plump\, v. t. [imp. & p. p. Plumped; p. pr. & vb. n. Plumping.] 1. To make plump; to fill (out) or support; -- often with up. [1913 Webster]
To plump up the hollowness of their history with improbable miracles. --Fuller. [1913 Webster]
2. To cast or let drop all at once, suddenly and heavily; as, to plump a stone into water. [1913 Webster]
3. To give (a vote), as a plumper. See Plumper, 2. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Plump \Plump\ (pl[u^]mp), a. [Compar. Plumper (pl[u^]mp"[~e]r); superl. Plumpest.] [OE. plomp rude, clumsy; akin to D. plomp, G., Dan., & Sw. plump; probably of imitative origin. Cf. Plump, adv.] 1. Well rounded or filled out; full; fleshy; fat; as, a plump baby; plump cheeks. --Shak. [1913 Webster]
The god of wine did his plump clusters bring. --T. Carew. [1913 Webster]
2. Done or made plump, or suddenly and without reservation; blunt; unreserved; direct; downright.
After the plump statement that the author was at Erceldoune and spake with Thomas. --Saintsbury. [Webster 1913 Suppl.]
From The Collaborative International Dictionary of English v.0.48:
Plump \Plump\, adv. [Cf. D. plomp, interj., G. plump, plumps. Cf. Plump, a. & v.] Directly; suddenly; perpendicularly. "Fall plump." --Beau. & Fl. [1913 Webster]