A circular sector is a portion of a circle that is enclosed by two radii of equal length and an arc. Synonyms for the term "circular sector" include pie slice, wedge, portion, and segment. A pie slice refers to the triangular shape of the sector, resembling a slice of pie. Similarly, a wedge describes a sector that is slanted, resembling a wedge of cheese. A portion refers to a part of the circle, while segment denotes a section that is separated from the rest of the circle. These terms are often used interchangeably and can help to describe different parts of a circle or pie chart.