Efydd, n. copper; brass
Efydden, n. a copper pan
Efyddiad, n. a coppering
Efyddu, v. to copper
Efyddwaith, n. copper work
Efyntau, pron. he or him, also
Efyrnig, n. a yearling goat
Effaith, n. an effect
Effeithiad, n. effectuation
Effeithio, v. to effectuate