APAD:A round peg in a square hole.

A round peg in a square hole.

This proverb means that someone who is unsuited or ill-equipped for a particular job or role is unlikely to succeed in that position. The phrase “round peg in a square hole” refers to the idea of trying to fit something into a space where it doesn’t belong, and the result is that it doesn’t fit properly and doesn’t work effectively. This proverb is often used to encourage people to find a job or career that suits their skills and abilities, rather than trying to force themselves into a role that is not a good fit for them.

It has several key meanings: 

• Incompatibility: The fundamental idea is a mismatch in shape or fit.
• Unsuited Person: Someone whose skills, personality, or character don't align with their role or surroundings.
• Feeling Out of Place: A person who feels uncomfortable, doesn't fit in, or doesn't belong in a particular group or situation.

The metaphor was originated by Sydney Smith in "On the Conduct of the Understanding", one of a series of lectures on moral philosophy that he delivered at the Royal Institution in 1804–06:

• If you choose to represent the various parts in life by holes upon a table, of different shapes,—some circular, some triangular, some square, some oblong,—and the person acting these parts by bits of wood of similar shapes, we shall generally find that the triangular person has got into the square hole, the oblong into the triangular, and a square person has squeezed himself into the round hole. The officer and the office, the doer and the thing done, seldom fit so exactly, that we can say they were almost made for each other.

Examples

"She felt like a square peg in a round hole at the new school until she made friends".

"He never quite fit in at the accounting firm; he was a square peg in a round hole".