ERE; ERF; ERG; ERN; ERR; GYP; NYE; ORE; PRE; PRY; PYE; PYX; REE; REO; REX; ROE; RYE.
EERY; EYRE; FREE; GREE; GREY; GYRE; GYRO; ORYX; PREE; PREY; PYRE; PYRO; RYND.
FREER; FRERE; PRYER; PYREX.