gwyllgi

== Welsh == === Etymology === Either from gwyll (“twilight”) +‎ ci (“dog”) or a variant form of gwylltgi from gwyllt (“wild”) and ci (“dog”). === Pronunciation === IPA(key): /ˈɡwəɬɡi/ === Noun === gwyllgi m (plural gwyllgwn) (mythology) A hellhound from Welsh folklore, appearing as a large black mastiff. === See also === Cŵn Annwn === Mutation === === Further reading === R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke, et al., editors (1950–present), “gwyllgi”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies