The correct spelling of the phrase is "more underage," not "more underaged." The word "underage" is an adjective that means "below the legal age or age of majority." It is pronounced as /ʌndəreɪdʒ/ (un-duh-reydj) with emphasis on the second syllable. Adding the suffix "-ed" to form the past tense is incorrect in this case as "underage" is not a verb. Therefore, using "more underaged" is a common spelling error that should be avoided.