underdeliver in English dictionary underdeliver Meanings and definitions of "underdeliver" To deliver less, or at an inferior level, than promised or expected verb To deliver less, or at an inferior level, than promised or expected more Grammar and declension of underdeliver underdeliver ( third-person singular simple present underdelivers, present participle underdelivering, simple past and past participle underdelivered) underdeliver (third-person singular simple present underdelivers, present participle underdelivering, simple past and past participle underdelivered) more Sample sentences with "underdeliver" Declension Stem Try again Authors