What does "plop down" mean?

To sit or lie down heavily and inelegantly.

What is a synonym for "plop down"?

Common synonyms include: cave, cave in, decline, droop, flop, flump.

verb, slang

verb, slang ·Moderate ·College level

Verb

1
To sit or lie down heavily and inelegantly. ambitransitive, informal
"They plopped themselves down on the bed."
2
To put down (something) in a heavy way. informal, transitive
"He plopped his wallet down."
3
To pay. US, informal, transitive
"I can't just plop down $50 for any old pair of jeans."

"They plopped themselves down on the bed."