Definify.com
Webster 1913 Edition
underage
un′der-ageˊ
(ŭn′dẽr-ĭj)
, Adj.
Shortage or deficiency in amount; shortfall.
[Obs.]
2.
Not having arrived at adult age, or at years of discretion; hence, raw; green; immature; boyish; childish.
[Obs.]
I myself have loved a lady, and pursued her with a great deal of
under-age
protestation. J. Webster.