plop down

phrasal verb

plopped down; plopping down; plops down

informal

1

: to sit or lie down in a heavy or careless way

They plopped down on the floor.

He plopped himself down in the chair.

2

: to drop or place (something or someone) in a heavy or careless way

He plopped the tray down.

3

US : to pay or spend (money)

I can't afford to just plop down $30 for a T-shirt.

He'd already plopped a lot of money down for legal fees.