Floruit (, ), abbreviated fl. (or occasionally flor.), Latin for "he/she flourished", denotes a date or period during which a person was known to have been alive or active. In English, the word may also be used as a noun indicating the time when someone flourished.
Broadly, the term is employed in reference to the peak of activity for a person, movement, or such. It is used in genealogy and historical writing when a person's birth or death dates are unknown. For example, if there are wills attested by John Jones in 1204 and 1229, and a record of his marriage in 1197, a record concerning him might be written as "John Jones (fl. 1197-1229)".
In some cases, it can be replaced by the words "active between [date] and [date]", depending on context and if space or style permits.