noun
admission gate; entrance gate; entrance
Refers to the physical gate or entrance point where admission is controlled, such as at a venue, event, or facility.
コンサート会場の入場口は長い列ができていた。
There was a long line at the admission gate of the concert venue.
入場口でチケットを見せてください。
Please show your ticket at the entrance gate.
出口 is an exit, the opposite of an entrance.
Compound of 入場 (にゅうじょう, 'admission') and 口 (ぐち, 'gate' or 'opening').