1. a section created by a plane cutting a solid perpendicular to its longest axis (Freq. 3) • Derivationally related forms: cross-sectional • Hypernyms: section, plane section • Hyponyms: profile 2. a sample meant to be representative of a whole population • Derivationally related forms: cross-sectional • Topics: statistics • Hypernyms: sample 3.(physics) the probability that a particular interaction (as capture or ionization) will take place between particles; measured in barns • Topics: nuclear physics, atomic physics, nucleonics • Hypernyms: probability, chance