Verb
underdeliver (third-person singular simple present underdelivers, present participle underdelivering, simple past and past participle underdelivered)
To deliver less, or at an inferior level, than promised or expected
According to Dr. Kelly Brogan, antidepressants not only overpromise and underdeliver, but their use may permanently disable the body’s self-healing potential. Source: Internet
Perhaps the simplest way to overpromise and underdeliver to a candidate is to focus too much of the pre-hire communications on things that aren’t related to their work. Source: Internet