malformation

noun

mal·​for·​ma·​tion ˌmal-fȯr-ˈmā-shən 

-fər-

: irregular, anomalous, abnormal, or faulty formation or structure

Examples of malformation in a Sentence

The condition is marked by malformation of the spine.

She underwent surgery to correct a heart malformation.

Recent Examples on the Web

For pregnant women, exposure can lead to fetal malformations or death. — Antonio María Delgado, Miami Herald, 24 Mar. 2026

At 14 weeks, Martinez learned the baby had a rare, severe congenital brain malformation. — Cindy Krischer Goodman, Sun Sentinel, 2 May 2026

If the fetus survives, long-term developmental delays, blindness, hearing loss, permanent teeth and bone malformation, heart defects and rashes can occur. — Casey Pinto, The Conversation, 1 May 2026

Research has linked phthalates with reproductive problems such as genital malformations and undescended testes in baby boys and lower sperm counts and testosterone levels in adult males. — Sandee Lamotte, CNN Money, 31 Mar. 2026

Word History

First Known Use

1800, in the meaning defined above

Rhymes for malformation

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

Kids Definition

malformation

noun

mal·​for·​ma·​tion ˌmal-fȯr-ˈmā-shən 

-fər-

: a misshapen, abnormal, or faulty formation or structure

malformation of the knee joint

Medical Definition

malformation

noun

mal·​for·​ma·​tion ˌmal-fȯr-ˈmā-shən, -fər- 

: irregular, anomalous, abnormal, or faulty formation or structure

congenital malformations