The verb run has close to 100 different meanings in English. We won’t run through them all here, but to give you an idea of the word’s range: a person can run for office, a climbing vine can run up the side of a house, and a carefully devised plan can run amok. Most commonly, though, run means “to go quickly” or “to move with haste.” The verb sprint is a strong synonym for this sense of run when the movement under discussion is at full speed. Sprint is far more specific than run, and it mostly occurs in the context of sports (The linebacker intercepted the ball and sprinted 20 yards for a touchdown). Though it’s sometimes used off the field (or racetrack) to talk about moving quickly out of excitement or anticipation: The siblings sprinted down the stairs to greet their new puppy.
The verb upset can mean either “to overturn” (to upset a table, a glass of water) or, more commonly, “to disturb mentally or emotionally” (The incident upset her). When applied to people and their internal state, upset implies a degree of distress, sometimes even anger. The synonym fluster suggests agitated confusion, and it is often used in situations when a person is taken off guard or is discombobulated by unanticipated behavior. If, for instance, you are giving an important presentation at work, and someone, seemingly out of the blue, asks you a series of vaguely antagonistic questions—well, that might fluster you! In such a situation, unless you are a seasoned pro, you might lose your train of thought and struggle to get back on track.
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.