underride /ˌʌndəˈraɪd/noun 1verb 1forms 4 noun1 •A vehicle accident in which one vehicle partially slides underneath another. verb1 •The action of a vehicle sliding under another in the context of an accident.Also needed, they said, is better design to prevent fuel-tank rupture and to prevent low vehicles from underriding trucks and buses. — 1968 formsunderrode · underridden · underriding · underrides