Cer-e-mo-ny, defod, arfer, seremoni
Cer-tif-i-cate, tystysgrif, tysteb: ysgrifdystio, tystebu
Char-ac-ter-ize, nodweddu, arwyddnodi
Char-i-ta-ble, hael, elusengar
Chris-tian-i-ty, cristionogaeth
Chro-nol-o-gy, amseryddiaeth, amsereg
Chro-nom-e-ter, awriadur; amseriadur
Cir-cu-la-tion, cylchrediad, cylchdroad; rhediad; taeniad
Cir-cum-cis-ion, enwaediad; blaendoriad
Cir-cum-fer-ence, amgylchedd, cwmpas