flaw
The definition for flaw is "An imperfection." Used in a sentence: The otherwise perfect diamond had a tiny flaw that reduced its value.
futile
The definition for futile is "Without purpose, completely ineffective." Used in a sentence: Arguing with Andrew is futile because he never changes his mind.
heed
The definition for heed is "To pay attention to." Used in a sentence: "Heed my advice," the fortuneteller warned Sebastian when he tried to ignore her prophecy.
inflammatory
The definition for inflammatory is "Tending to excite anger." Used in a sentence: Garth's inflammatory remarks at the party made Gwen furious.
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.