The Collaborative International Dictionary of English v.0.48:
Spleenwort \Spleen"wort`\, n. [Spleen + wort; cf. L. splenium, asplenium, Gr. ????, ????, ???. ] (Bot.) Any fern of the genus Asplenium, some species of which were anciently used as remedies for disorders of the spleen. [1913 Webster]WordNet (r) 3.0 (2006):
spleenwort n 1: any of various chiefly rock-inhabiting ferns of the genus Asplenium