In-ter-lo-cu-tion, cydsiarad
In-ter-pre-ta-tion, dehongliad
In-ter-ro-ga-tion, holiad; nod o holiad (?)
In-tol-er-a-ble, anoddefadwy
In-tox-i-ca-tion, meddwdod
In-tre-pid-i-ty, glewder, dewrder
In-val-u-a-ble, uwchlaw gwerth, tragwerthfawr
In-va-ri-a-ble, digyfnewid
In-ves-ti-ga-tion, olrheiniad
In-vol-un-ta-ry, anfoddus, anewyllysgar