A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the large leaves of cycads and palms (Arecaceae).
...or may be of different lengths. The leaves are generally small, although they sometimes achieved a length of one metre (three feet) in the gigantic Lepidodendron. Generally each leaf, or microphyll, is narrow and has an unbranched midvein, in contrast to the leaves of the ferns and seed plants, which generally have branched venation.