BABYISH, BABYISHNESS
ADJECTIVES
1535 ► BABISHED made babyish or childishly silly → obs.
1553 ► BABISH babyish, childish, silly; used contemptuously → arch.
1881 ► AVISH → AYVISH half-witted, silly; babyish, aping childishness → Eng. dial.
1896 ► TIDDY babyish; tiny → Eng. dial. (Bk.)
ADVERBS
1567 ► BABISHLY in a babyish fashion → Sc.
NOUNS
1557 ► BABISHNESS babyishness → obs.
NOUNS, PERSON
2003 ► BABY ASS someone who is babyish → US teen sl.
Lexicophilia 