How to say "burr" in Japanese

• いが
  nounThe prickly husk — botanically the cupule — that encases a chestnut; think of gathering chestnuts in autumn. It also covers a husk or case more generally, and is normally written in kana alone.
• バリ
  nounThe rough edge or sliver of metal left on a workpiece after cutting or machining; this is the word for 'burr' in metalworking and manufacturing contexts.
  まず、バリを剥はがしてください。↗

  First, remove the burrs.
• カエリ
  nounA synonym of バリ for the rough edge left on metal by machining. It is a less common alternative, so バリ is the choice to learn first for this engineering sense.
• イガイガ
  nounA doubled form of いが meaning the same spiky chestnut burr. For this sense いが is the word to reach for; this variant is one you are likelier to meet than to need.
• くっつき虫くっつきむし
  nounNot a husk or a metal edge but the clinging seeds themselves: prickly seedheads that hitch a ride on fur and clothing, named for how they stick like little bugs.

For the spiky chestnut husk use 「いが」 (or the doubled 「イガイガ」); for the rough edge left on machined metal use 「バリ」 or 「カエリ」; for prickly seeds that cling to clothes and fur, 「くっつき虫」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• いがburr (e.g. chestnut)
• ばりburr (e.g. on a machined edge)
• かえりburr (of a machined edge)
• いがいがbur (of a chestnut, etc.)
• くっつき虫くっつきむしbur (prickly seeds or seedheads that stick to fur and clothes)
• ひっつき虫ひっつきむしbur (prickly seeds or seedheads that stick to fur and clothes)