Synonyms of underage

2 Syllables
leanness, scantness, youthful, junior, tightness, shortfall, minor, schoolgirl
3 Syllables
scarceness, deficit, inaptness, skimpiness, shortage, scantiness, faultiness
4 Syllables
juvenile, defalcation, adolescent, underaged
5 Syllables
incompleteness, inadequacy, inadequacies, defectiveness