The Collaborative International Dictionary
Pileorhiza
Pileorhiza \Pi`le*o*rhi"za\, n.; pl. Pilorhiz[ae]. [NL., fr. Gr. ? a cap + ? root.] (Bot.) A cap of cells which covers the growing extremity of a root; a rootcap.
Wiktionary
pileorhiza
n. (context botany English) A cap of cells covering the growing extremity of a root; a rootcap.