cephalopelvic disproportion I. ceph·a·lo·pelvic disproportion\ˌ ̷ ̷ ̷ ̷(ˌ) ̷ ̷+...-\noun Etymology:cephal- + pelvic : a condition in which the maternal pelvis is small in relation to the size of the fetal head II. ceph·a·lopelvic disproportion\¦sefə(ˌ)lōˌ…-\noun Etymology:cephal- + pelvic : a condition in which a maternal pelvis is small in relation to the size of the fetal head