Emily Dickinson Lexicon

SEP'AL, n. [from L. sepio.]

In botany, a distinct part of that sort of calyx which is called a perianth. When a perianth consists of but one part it is said to be monosepalous, when of two or more pans, it is said to be di, tri, tetra, pentasepalous, etc. When of a variable and indefinite number of parts, it is said to be polysepalous.