noun
A somewhat old-fashioned or colloquial term for a miser. Often used in a teasing or derogatory way.
あの吝ん坊は一円も出さない。
That miser won't spend even one yen.
彼は吝ん坊だから、誰も一緒に食事に行きたがらない。
He's such a stingy person that nobody wants to go out to eat with him.
From しわん (miserly, stingy) + 坊 (boy, suffix for a person). The origin of しわん is uncertain, but it may be related to しわい (stingy) or しわしわ (wrinkled, suggesting a tight-fisted image).