Geiriadur Prifysgol Cymru: A Dictionary of the Welsh Language (GPC) is the online version of A Dictionary of the Welsh Language, the historical dictionary of Welsh similar in scope to the Oxford English Dictionary. Funded by the Welsh government, the decades-long print project was completed in 2001 and the digital version was begun in 2011 and is an ongoing project. The GPC contains entries dating back to the earliest references to Welsh and contains many entries spanning the medieval period. Entries contain grammatical information as well as a definition and dated historical sources to the words under consideration. Users may search entries in either Welsh or English.
The project is free to use and has an active web presence that updates users on the project’s status.