normal subgroup

Etymology
The term was coined by.

Noun

 * 1)  A subgroup H of a group G that is invariant under conjugation; that is, for all elements h of H and for all elements g in G, the element ghg−1 is in H.

Translations

 * Finnish: normaali aliryhmä
 * French: sous-groupe distingué
 * German:, normale Untergruppe
 * Icelandic: normleg hlutgrúpa, óbreytt hlutgrúpa
 * Italian: sottogruppo normale, sottogruppo invariante
 * Polish: podgrupa normalna
 * Spanish: subgrupo normal