理兒

reason

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

child / son

non-syllabic diminutive suffix / retroflex final

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