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.
drab
The definition for drab is "Dull, monotonous." Used in a sentence: The drab winter scene made Keisha long for the vibrant colors of spring.
elusive
The definition for elusive is "Hard to grasp." Used in a sentence: The words to the song are elusive, as the singer tends to mumble.
facade
The definition for facade is "false or superficial appearance." Used in a sentence: Emily's smile is just a facade masking her broken heart.
pallid
The definition for pallid is "Lacking color." Used in a sentence: The nurse was worried by the patient's pallid face and shallow breathing.