in

(not comparable)At or towards the interior of a defined space, such as a building or room.

Suddenly a strange man walked in.

Would you like that to take away or eat in?

herein, hinein

(not comparable)Towards the speaker or other reference point.

They flew in from London last night.

For six hours the tide flows in, then for another six hours it flows out.

(not comparable)So as to be enclosed or surrounded by something.

Bring the water to the boil and drop the vegetables in.

I was tired enough to snuggle in with the dogs on the couch and sleep there.

(not comparable)After the beginning of something.

The show still didn't become interesting 20 minutes in.

(in compounds, not comparable)Denotes a gathering of people assembled for the stated activity, sometimes, though not always, suggesting a protest.

sing-in, pray-in, hug-in; see also be-in, love-in, sit-in, teach-in.