A list of words that I have recently looked up.

• l'esprit de l'escalier: l'esprit de l'escalier or esprit d'escalier (stairway wit) is thinking of a clever comeback when it is too late.
• exacerbate: make worse.
• seersucker: a light puckered fabric (usually striped).
• Fregoli delusion: a rare disorder in which a person holds a delusional belief that different people are in fact a single person who changes appearance or is in disguise.
• ecological fallacy: an error in the interpretation of statistical data in an ecological study, whereby inferences about the nature of specific individuals are based solely upon aggregate statistics collected for the group to which those individuals belong. This fallacy assumes that individual members of a group have the average characteristics of the group at large. Stereotypes are one form of ecological fallacy, which assumes that groups are homogeneous.