Describes a person who is greedy for food or material things. Often used in a mildly scolding or teasing way. The word is somewhat colloquial and carries a negative, but not extremely harsh, tone.
That kid is greedy and always wants snacks.
Because I'm a glutton, I try too hard to get my money's worth at all-you-can-eat places.
Kana spelling is standard; usually written in kana.
Kanji spelling using 卑 (lowly, base). Rarely used; the kana form is strongly preferred.
Derived from the adjective 卑しい (いやしい, 'greedy, lowly') plus ん坊 (a suffix meaning 'person' or 'child', often used in nicknames). The exact historical development is uncertain, but the word has been used in colloquial Japanese for centuries.