prill /pɹɪl/noun 7verb 4forms 3 noun7 •a pellet, a granule, a small beadPrills are free-flowing pellets developed for fertilizer as a coarse product with little setting tendency that can be spread easily and smoothly. — 2000 •A nugget of virgin metal. •The button of metal from an assay. •rich copper ore remaining after removal of low-grade material; a droplet of copper suspended in molten slag •a rill, a small stream •The brill, a kind of flatfish. •(no longer used) a spinning top verb4 •to produce pellets by forming a molten substance into droplets which solidify while falling •to flow, spurt •(dialect, UK) To grow sour. •(dialect, UK) To become tipsy. formsprilled · prilling · prills