i Register
In some senses, btm is marked as colloquial, euphemistic. Watch for register when choosing this word.
PREP.
on
noun
Alternative letter-case form of btm (“bottom”).
noun
Abbreviation of bottom.
That child needs a smack on the btm!
They sat on their btms all day and got nothing done.
That child needs a smack on the btm!
WiktionaryThey sat on their btms all day and got nothing done.
Wiktionaryi Register
In some senses, btm is marked as colloquial, euphemistic. Watch for register when choosing this word.