Definitions of fern:

• noun:   any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores
• name:  A female given name (rare: 1 in 4166 females; popularity rank in the U.S.: #552)
• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #11558)