Terfynaf, n. a boundary line
Terfyn-gylch, n. a horizon
Terfyniad, n. a terminating
Terfynol, a. terminating
Terfynoldeb, n. finitness
Terfynu, v. to limit; to end
Terfysg, n. tumult
Terfysgol, a. tumultuous
Terfysgedd, n. tumultuousness
Terfysgiad, n. making a tumult