“in”

To or towards the inside of.

Such as, among which; introducing one or more parts of the group or topic just mentioned.

Something that provides a definitive characterization or description of the nature and attributes of a specified entity.

Of or concerning the association called the International.

In the place of something (usually mentioned earlier); as a substitute or alternative.

To bring into a group, class, set, or total as a (new) part or member.

The tendency to work persistently.

The interior or inner part.

At any rate: anyhow, regardless (emphasizing that a point doesn't matter or hardly matters).

Lying on a bed.

Explicitly, in writing, clearly and without doubt or misunderstanding, without any grey areas.

In a sequence.

Without information.

Said or done almost simultaneously, in one sequence.

Technical matters concerning baseball generally not apparent or of interest to spectators.

One cannot obtain what one desires by being cautious; one must be aggressive.

The time of occurrence of an event that will never happen.

If a friend is in need of help, it is beneficial and wise to help them.

In the sense of.

To enter a place by force or illicit means.

To collide with.

To collapse inward or downward.

To announce or record one's own arrival at a hotel, airport etc.

To make a contribution; help in a small way; especially, to pay for a part of something.

To enter.

Of a soldier, to get into position in a rank.

To get into or inside something, literally or figuratively.

To enter something quickly, usually a mode of transport.

To let someone or something come in; to admit someone or something in.

A relationship, such as a marriage, that is happy and successful, sometimes because the partners are very compatible.

To flow or flood into something or somewhere.

To place inside.

To collect something such as leaves into a pile, often with a rake.

To reveal a non-obvious or hidden aspect of a plan or situation to (a person).

To substitute for; to replace

To pull the blankets or duvet up over (someone in bed); to put (someone) to bed.

To submit something; to give.

To become.

When situated in a foreign place, it is wise to follow the local customs.

To ponder, to go over in one's mind.