The definition for incumbent is "Necessary as a duty or responsibility." Used in a sentence: It was incumbent on Jack to attend his father's retirement party. The definition for extant is "currently existing.", the definition for cunning is "Showing clever insight.", and the definition for fragile is "Delicate."

The definition for rancorous is "Marked by deep ill–will." Used in a sentence: The rancorous competition between the two chess clubs actually ended in a brawl. The definition for combustion is "act of burning.", the definition for drab is "Dull, monotonous.", and the definition for retroactive is "effective as of a prior time or condition."

The definition for nurture is "To further the development of." Used in a sentence: Our cat made a nest of blankets to nurture her newborn kittens. The definition for gruff is "rough or stern in manner or speech.", the definition for heed is "To pay attention to.", and the definition for repel is "To resist, reject."

The definition for curtail is "To make less." Used in a sentence: Doreen decided to curtail her spending after she bounced a check. The definition for commemorate is "to mark by a ceremony.", the definition for iridescent is "Having a lustrous or attractivve quality.", and the definition for inviolable is "Secure from assault of trespass."

The definition for melee is "A tumultuous fight among several people." Used in a sentence: After the game, a melee broke out between fans of the opposing teams. The definition for fickle is "lacking constancy, changeable.", the definition for naive is "Lacking worldy wisdom.", and the definition for drub is "To defeat decisively."