理儿

reason

variant of 人[ren2] / "person" radical in Chinese characters (Kangxi radical 10), occurring in 兒, 兀, 兄 etc

child / son

non-syllabic diminutive suffix / retroflex final

texture / grain (of wood) / inner essence / intrinsic order / reason / logic / truth / science / natural science (esp. physics) / to manage / to pay attention to / to run (affairs) / to handle / to put in order / to tidy up

erhua variant of 認死理|认死理[ren4 si3 li3]