A cubic inch (plural: cubic inches) is a non-SIunit of volume, equal to the volume of a cube with sides of one inch.Cubic inches are still sometimes used as a unit of measurement (in engineering contexts, not household contexts) in the United States and United Kingdom, although SI is continuing to gradually displace non-SI usage.
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Noun 1. the volume equal to a cube one inch on each side (synonym) cu in (hypernym) volume unit, capacity unit, capacity measure, cubage unit, cubic measure, cubic content unit, displacement unit, cubature unit