The act of going in and out; entering and exiting (people or things).
この建物は出入りが自由です。
People are free to enter and exit this building.
深夜に不審な出入りがあったので、警備員が確認した。
There were suspicious comings and goings late at night, so the security guard checked.
出入り口はあちらの扉です。
The entrance/exit is that door over there.
Frequenting or regularly visiting a place or having regular dealings with someone.
彼はあの喫茶店に出入りしている常連だ。
He is a regular who frequents that café.
作家は出版社に頻繁に出入りしている。
The writer frequently goes to the publishing company.
あの政治家は業界の会合に出入りしていることで知られている。
That politician is known for his regular attendance at industry meetings.
Income and expenditure; cash inflow and outflow.
家計の出入りを毎月記録している。
I record the household's income and expenditure every month.
今月の出入りは赤字だ。
This month's balance of income and expenditure is in the red.
会社の出入りを帳簿に正確に付ける必要がある。
It's necessary to record the company's inflows and outflows accurately in the books.
Increase and decrease; fluctuation — changes where amounts go up and down.
この店は季節によって客の出入りが大きく変わる。
This shop's customer flow fluctuates greatly depending on the season.
為替相場の出入りが激しく、企業の資金繰りに影響が出た。
Large fluctuations in the exchange market affected companies' cash management.
A fight, quarrel, or dispute — a rarer/old-fashioned sense of the word.
土地境界をめぐって小さな出入りが起きた（古い表現）。
A small dispute arose over the land boundary (archaic expression).
Indentations such as inlets or bays — concave parts of a coastline (a specialized/rare usage).
この海岸は出入りが多くて船の停泊に適している。
This coast has many inlets and is suitable for boats to moor.