Vespertine is a term used in the life sciences to indicate something of, relating to, or occurring in the evening. In botany, a vespertine flower is one that opens or blooms in the evening. In zoology, the term is used for a creature that becomes active in the evening, such as bats and owls. Vespertine animals are frequently described as nocturnal, although this usage is not strictly correct.
The term vespertine is derived from the Latin word vesper, meaning evening. A synonym for vespertine used in both botany and zoology is crepuscular. However, crepuscular refers to both early morning and early evening.