In-sep-a-ra-ble, anwahanadwy
In-sig-nif-i-cance, ansylwedd
In-sig-nif-i-cant, disylwedd, dibwys
In-sin-u-a-tion, truthymlusgiad
In-sta-bil-i-ty, anwadalwch
In-stan-ta-ne-ous, cythrymol, disyfyd
In-suf-fer-a-ble, annyoddefadwy
In-sur-mount-a-ble, anorchfygadwy
In-tel-lect-u-al, deallawl, dealledigol
In-tel-li-gi-ble, dealladwy