Amelia is the birth defect of lacking one or more limbs. It can also result in a shrunken or deformed limb. The term may be modified to indicate the number of legs or arms missing at birth, such as tetra-amelia for the absence of all four limbs. A related term is meromelia, which is the partial absence of a limb or limbs. The term is from Greek ἀ- "lack of" plus μέλος (plural: μέλεα or μέλη) "limb"