The verb commemorate usually refers to the observance of an already established holiday or anniversary dedicated to remembering a person or event of the past (to commemorate Bastille Day). Though this word is sometimes used to talk about somber circumstances (to commemorate the dead by a moment of silence), commemorate is more commonly paired with uplifting terms: we commemorate victories, anniversaries, and great and historic things. The synonym memorialize is a bit more personal, and is very strongly associated with honoring or preserving the memory of those who have departed. When people memorialize something, they usually do so in some specified way: The town council decided to memorialize the late mayor with an annual day. The Lincoln Memorial was created to memorialize Lincoln in an enduring marble sculpture, just as an engraved urn—or a memorial service—memorializes a loved one.

An award is something given as a reward for merit or distinction. Someone who wins an award may receive a monetary reward or a trophy, medal, ribbon, or certificate. The noun accolade can be used as a synonym for award, although, if your goal is to be purely informative or you are referring to a specific award, accolade in American English may come off sounding unnatural, or extra. Accolade can mean any award, honor, or public expression of praise, such as a five-star review or a laudatory statement from a notable person or group. In fact, accolade is most frequently used to refer to an instance of praise (The play received accolades from the press), or as a catch-all that covers multiple forms of recognition, which may explain why this word is usually found in the plural form. Whereas award by itself has fairly neutral connotations—it is equally applicable to your third-grade spelling prize and an Oscar—the word accolade tends to suggest a prestigious award, a high honor, or high, enthusiastic praise. The prestige implied by accolade is perhaps a vestige of its earliest meaning: a light touch on the shoulder with the flat side of the sword or formerly by an embrace, done in the ceremony of conferring knighthood.

The adjective former means, broadly, earlier in time (during a former stage in the proceedings) or, of two things in succession, earlier in order (Our former manufacturing process was too costly). Erstwhile isn’t a viable synonym in these cases, but it does overlap in meaning with former in phrases like the former president, a former dancer, former members, her former husband, or my former home, where former refers to someone or something in terms of what they at one time were, but no longer are. Erstwhile has a literary ring to it; when former feels a bit too objective or emotionless or final, erstwhile is there to (potentially) soften your description of a role or relationship as no longer existing. This could be why some of the most common uses of this word are in the phrases erstwhile ally, friend, colleague, partner, and enemy, although you’re still far more likely to find former allies than erstwhile allies. Erstwhile’s use as an adjective (it was originally an adverb) has seen a slow but steady increase over the past century, and if that continues, it may eventually stake out clearer territory. It’s not over until it’s over.