ôl-ddyddio

== Welsh == === Etymology === From ôl (“back”) +‎ dyddio (“to date”). === Pronunciation === IPA(key): /ˌoːlˈðəðjɔ/ === Verb === ôl-ddyddio (first-person singular present ôl-ddyddiaf) to backdate ==== Conjugation ==== === Mutation === === Further reading === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “ôl-ddyddio”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies