dubious
The definition for dubious is "Questionable." Used in a sentence: Karl found Kevin's claim that he was sick dubious, as he had just seen him playing football.
implement
The definition for implement is "To carry out or accomplish." Used in a sentence: All Randolph needed to implement his plan was a moonless night and a long rope.
periodic
The definition for periodic is "Occurring at regular intervals." Used in a sentence: The periodic innterruptions of the cuckoo clock prevented Li from concentrating.
stern
The definition for stern is "Harsh, severe." Used in a sentence: The stern principal canceled the prom after the seniors played a silly prank.
supple
The definition for supple is "Flexible." Used in a sentence: The supple leather coat draped like soft cloth around her shoulders.