Hole in the wall is a common phrase used to describe a small, unplanned opening on a larger surface. However, there are various synonyms for this phrase that can be used in different contexts. For example, "crack in the wall" can be used to refer to a small opening in a wall caused by cracks while "gap in the wall" can be used to describe a space left unplanned during the construction of a wall. Alternately, "perforation in the wall" is a more formal synonym used to describe a perfectly round hole that is not accidental. Other variations include "crevice in the wall," "cavity in the wall," and "rent in the wall." These synonyms can help paint a clearer picture when describing the small openings in a wall.