0 the quality of someone or something, especially someone's ability: --
1 the width of the inside of a pipe, especially of the long cylinder-shaped part of a gun, or the width of a bullet --
2 the degree of quality or excellence of something or someone: --
3 the width of the inside of a pipe, esp. of the long, cylindrical part of a gun, or the width of a bullet: --
a .22-caliber rifle