The Collaborative International Dictionary
Clumper
Clumper \Clump"er\, v. t. [Cf. G. kl["u]mpern to clod. See Clump, n.] To form into clumps or masses. [Obs.]
Vapors . . . clumpered in balls of clouds.
--Dr. H.
More.
Wiktionary
clumper
Etymology 1 n. A grass or other plant that tends to form clumps. Etymology 2
vb. (context obsolete intransitive English) To form into clumps or masses.
Usage examples of "clumper".
Georgia lolloped along on Clumper, a war bunny much like Thumper except for an ear with a bend in it.
Georgia saw the rostler knew what she was doing and the hutch hands were reliable, she left Thumper and Clumper with them without too many regrets.