Both words refer to the act of misleading, tricking, or deceiving someone, usually for one’s own advantage or gain. Deception is the broader term, covering all ways of misleading people, from false appearances to lies: deception in advertising. Subterfuge is a category of deception that involves the use of cunning tricks or stratagems in order to get away with something. Subterfuge emphasizes the tricks themselves, particularly tricks that (like a smoke screen) hide or disguise what is actually going on: Going out would require subterfuge, so I set my music player to start one hour after I’d slipped out through my bedroom window. Politics, not espionage, is by far the most frequent context for subterfuge.

Both words can refer to a sudden spell of heightened emotion or activity, which for both words is an extension of a medical definition for a sudden attack or intensification of a disease. Paroxysm conveys a violent, serious spell of emotion or activity more consistently than fit, but both words are used of strong emotions: a fit of rage; paroxysms of anger, rage, laughter, grief. Fit can also be applied (without facetiousness) to the onset of less acute, intense states: a fit of inactivity; a fit of nostalgia. When eruptions of emotion and activity are attributed to whole populations or geopolitical entities, paroxysm is much more likely to be used: global paroxysms; a paroxysm of nationalism.

Flashy and gaudy describe things that are conspicuously showy and intended to attract attention and impress. Flashy suggests a person’s blatant, glitzy display of wealth (real or apparent): flashy cars; flashy clothes. Gaudy is less about personal lifestyle and consumption and more about taste and aesthetics. Gaudy suggests excessively bright colors and ornamentation, often tasteless or cheap: gaudy Christmas lights; gaudy gold ring; gaudy colors; gaudy costume.