She is side eyeing her friend's new outfit.

She side eyed him when he walked into the room.

She gave him side eyes when he made a rude comment.

She side eyes him whenever he talks.

She gave him a side eye when he made that comment.

She side eyes her coworker whenever he speaks.

She always errs on the side of caution.

I erred on the side of caution and decided not to take any risks.

I am erring on the side of caution by double-checking all the information.

He is the last remaining member of the spear side of the family.