Refers to an approach or argument that relies strictly on logic and reason, often in contrast to emotional or intuitive approaches. Commonly used in phrases like 理詰めで行く or 理詰めの議論.
Compound of 理 (り, 'reason, logic') and 詰め (つめ, from 詰める, 'to pack, to fill'). Literally 'packed with reason', suggesting a thorough, logic-driven approach.