-rhi·za noun combining form or-r·rhi·za\ˈrīzə\ (plural-rhi·zae \-(ˌ)zē\ ; or-rhizasor-r·rhi·zaeor-rrhizas) Etymology: New Latin, from Greek rhiza root 1.: root : part resembling or connected with a root < coleorhiza > < mycorrhiza > 2.: plant having (such) a root — in genus names in botany < Balsamorrhiza >