Dictionary

A bounding straight edge of a two-dimensional shape.

Example: A square has four sides.

A flat surface of a three-dimensional object; a face.

Example: A cube has six sides.

One half (left or right, top or bottom, front or back, etc.) of something or someone.

Example: Which side of the tray shall I put it on?  The patient was bleeding on the right side.

A region in a specified position with respect to something.

Example: Meet me on the north side of the monument.

To ally oneself, be in an alliance, usually with "with" or rarely "in with"

Example: Which will you side with, good or evil?

To lean on one side.

To be or stand at the side of; to be on the side toward.

To suit; to pair; to match.

To clear, tidy or sort.