Both flair and panache can be used to refer to a quality of distinctive stylishness that makes something interesting or attractive. It’s common to say that someone does something (dresses or cooks, for example) with flair or with panache, or even with flair and panache. And we’re often told what ingredient or item will add flair or panache (or both) to a room, an outfit, or a dish. These nouns are interchangeable to a point, but their differences should not be ignored, as often happens. Panache is a manner of doing something with flamboyant confidence, vigor, and energy, as well as style or skill. Panache also has a wider range of application than flair—someone can play a sport, direct films, or lead an organization with panache.

Old-fashioned and antiquated both refer to something dating from the past. Old-fashioned usually applies to the appearance or manner of something, either disparaging it as being out of date (an old-fashioned hat) or approving it as being superior to the present day (good old-fashioned courtesy) or possessing charm (old-fashioned barber shop). Antiquated can be used to simply mean very old or from another age, as an antiquated building, but it most often connotes something too old to be useful, functional, or relevant, as antiquated systems and antiquated laws. Something antiquated is usually a problem because it doesn’t meet present-day needs. These days our devices are at risk of becoming antiquated technology in just a few years.

Huge means extraordinarily large in bulk, quantity, or extent (a huge ship, a huge portion of ice cream). It's also used to describe things that are without limit (the huge genius of Mozart) and things that are very important or popular (the show was huge in Britain). When we describe something as gargantuan, we mean it’s of an extraordinary or astonishing size, dwarfing other things of its kind (a gargantuan whale, a gargantuan serving of pie). The adjective comes from Gargantua, a grotesque giant with an enormous appetite in the works of Rabelais. It’s frequently used with size and other similar nouns (consuming a gargantuan amount of energy, grown to gargantuan proportions). Like huge, gargantuan can also be used to talk about the seriousness or extent of non-material things, particularly problems: a gargantuan task or undertaking requires a gargantuan effort, which is no big deal for a giant, but for the rest of us seems almost impossible.