FACETIOUS Don't be so facetious ! Don’t be facetious about the meeting. They are discussing a very important topic which requires you to show some gravitas. She's just being playful . FACILE My child has a facile imagination in writing. While the middle aged people found the video game complicated, the teenagers thought it was facile and easily played. Since Ravi had studied for the exam, he earned a perfect score on the easy test. FALLACIOUS Their argument is based on fallacious reasoning. The argument is fallacious , for it is based on a set of factual flaws. I think this is an entirely erroneous argument, with little to no factual support. FASTIDIOUS My spouse is fastidious about her appearance. My father is a fastidious man who always has a complaint on his lips. A cat is a fussy animal that washes ...