microcephalynoun [ U ]
uk/ˌmaɪ.krəʊ.ˈsef.ə.li//ˌmaɪ.krəʊ.ˈsef.ə.li/specializedthe state of having a head that is smaller than normal, because the brain has not developed normally:
There has recently been a large increase in cases of microcephaly, potentially linked to the Zika virus.
microcephalic
adjective, noun [ C ] /ˌmaɪ.krəʊ.sɪfˈæl.ɪk//ˌmaɪ.kroʊ.səˈfæl.ɪk/specialized
a study of brain shape in human microcephalics
microcephalic children