gargantuan
The definition for gargantuan is "Gigantic." Used in a sentence: The gargantuan monster towered over the ten–story bulding.
incumbent
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.
rancorous
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.
servile
The definition for servile is "Fearfully submissive." Used in a sentence: Felicia's servile attitude annoyed her boss, who preferred an assistant with more backbone.
stifle
The definition for stifle is "To repress or discourage." Used in a sentence: Amy tried ineffectively to stifle her giggles after she read Susan's note in class.