also: いばりんぼ · えばりんぼ · えばりんぼう
noun
bossy person; braggart; overbearing person
Colloquial, often used for children or in light teasing. Describes someone who acts self-important, throws their weight around, or boasts excessively.
See also: 威張る
うちの弟は本当にいばりんぼうで、いつも命令ばかりしてくる。
My little brother is such a bossy boots, always ordering everyone around.
あの子はテストで百点取ったって、いばりんぼうみたいに自慢してたよ。
That kid was bragging like a big shot about getting a perfect score on the test.
The verb meaning 'to be arrogant' or 'to throw one's weight around'; いばりんぼう is a noun derived from it, describing a person who habitually does this.
Derived from the verb 威張る (いばる, 'to be arrogant') with the colloquial suffix ん坊 (んぼう/んぼ), which often forms playful or teasing nouns for people with a certain trait (compare けちん坊, 食いしん坊). The exact origin of the suffix is uncertain, but it likely comes from 坊 (ぼう, 'boy') with an inserted ん.