入门

入门	rù mén	entrance door / to enter a door / to learn the basics of a subject; introduction (to a subject); (attributive) entry-level
入	rù	to enter; to go into / to join; to become a member of / (bound form) to conform to (as in 入时) / abbr. for 入声 / (on product packaging, after {number n} + {classifier}) containing (n pieces) (from Japanese 入 "iri")
门	Mén	surname Men
门	mén	gate; door; doorway; gateway; opening (CL:扇) / valve; switch; other door-like or gate-like structure / way to do sth; knack; method; approach / family; household; lineage / (bound form) sect; school; faction (religious or academic) / (bound form) class; category; division; phylum / classifier for courses, fields of study, branches of technology, relatives by marriage, guns etc / (suffix) -gate (scandal)