diffident
The definition for diffident is "Lacking self–confidence." Used in a sentence: The diffident student never raised her hand in class, even when she knew the answer.
implausible
The definition for implausible is "Unbelievable." Used in a sentence: Claudia's implausible excuse failed to convince her teacher.
mundane
The definition for mundane is "Practical, ordinary." Used in a sentence: The flighty Caroline could not be troubled with mundane tasks such as paying her bills.
repentant
The definition for repentant is "Feeling regret." Used in a sentence: The repentant Dana admitted to cheating on the test.
surplus
The definition for surplus is "Excess." Used in a sentence: Trevor decided to freeze the surplus chili for next week's tailgate party.