beneficial
The definition for beneficial is "Helpful." Used in a sentence: there is no doubt that eating vegetables is beneficial to one's health.
epistolary
The definition for epistolary is "Contained or carried on in letters." Used in a sentence: The shoebox filled with letters was the ony remains of Ming's epistolary friendship with Emile.
mediate
The definition for mediate is "To come between parties in order to reconcile." Used in a sentence: The diplomatic Henry was able to mediate between the quarreling sisters.
prudent
The definition for prudent is "Marked by wisdom, shrewd." Used in a sentence: Manny was happy she followed Greg's prudent advice to study, as the test was difficult.
regurgitate
The definition for regurgitate is "To pour out or throw back." Used in a sentence: The teacher wanted us to examine ideas rather than to regurgitate memorized facts.