相棒

1. Origins, structure, and basic meaning

• Structure: 相棒, read あいぼう, is an established person term for a close working companion.
• Basic usage: 相棒 is a partner or companion who works alongside and relies on another.

2. Common pitfalls and similar expressions

• A close working partner
  • 相棒と frames joint action, while 相棒だ identifies the person as that partner; the relation is closer than mere acquaintance.