Cofrestr, n. a catalogue, a register
Cofrestriad, n. a registering
Cofrestru, v. to register
Cofrestrwr, n. registrar
Cofus, a. memorable; mindful
Cofweinydd, n. prompter
Cofwyl, n. memorable festival
Coffa, v. to remember
Coffadwriaeth, n. remembrance
Coffadwriaethol, commemorative