Malformation/ˌmælfɔːrˈmeɪʃn/ Definition 1 of 2Pro Tip 1/3Medical Context Used to describe abnormalities in body part structures, often serious. A congenital malformation can require medical intervention. Pro Tip 2/3Not Always Visible Malformations are not always externally noticeable; some are internal. The ultrasound revealed a renal malformation not seen outside. Pro Tip 3/3Serious Implications Using 'malformation' conveys a sense of significant and impactful irregularity. The malformation in her spine affected her mobility.