plunk (v.)

1805, "to pluck a stringed instrument;" 1808 in sense of "drop down abruptly;" 1888 as "to hit, wound, shoot." Probably of independent imitative origin in each case. Related: Plunked; plunking.

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Definitions of plunk from WordNet
plunk (v.)
make or move along with a sound as of a horse's hooves striking the ground;
Synonyms: clop / clump / clunk
plunk (v.)
set (something or oneself) down with or as if with a noise;
Synonyms: plank / flump / plonk / plop / plump down / plunk down / plump
plunk (v.)
drop steeply;
Synonyms: dive / plunge
plunk (v.)
pull lightly but sharply with a plucking motion;
Synonyms: pluck / pick
plunk (n.)
a hollow twanging sound;
plunk (n.)
(baseball) hitting a baseball so that it drops suddenly;
Synonyms: plunker
plunk (adv.)
with a short hollow thud;
Synonyms: plop