verb
plunks; plunked; plunking
informal
chiefly US :to pull or hit a string or key on a musical instrument with your fingers especially in a way that makes a brief, somewhat harsh sound [+ obj]
[+ obj] US :to hit (someone or something) especially with a ball
always followed by an adverb or preposition [+ obj] chiefly US :to drop or place (something or someone) in a forceful and often careless way :plop
plunk down
[phrasal verb] informal
plunk down (money) or plunk (money) down US :to pay or spend (money)
plunk down or plunk yourself down chiefly US :to sit or lie down suddenly in a careless way