上门

to drop in / to visit / to lock a door / (of a shop) to close / to go and live with one's wife's family, in effect becoming a member of her family

used in 上聲|上声[shang3 sheng1]

(bound form) up; upper; above; previous / first (of multiple parts) / to climb; to get onto; to go up / to attend (class or university) / (directional complement) up / (noun suffix) on; above

gate / door / CL:扇[shan4] / gateway / doorway / CL:個|个[ge4] / opening / valve / switch / way to do something / knack / family / house / (religious) sect / school (of thought) / class / category / phylum or division (taxonomy) / classifier for large guns / classifier for lessons, subjects, branches of technology / (suffix) -gate (i.e. scandal; derived from Watergate)

to come to sb's door / to call on sb

house call fee / callout fee

bricks-and-mortar customer; walk-in customer

to invite the devil to one's house (idiom) / to introduce a potential source of trouble

to close the door (when going through it)