gwrthfater

== Welsh == === Etymology === gwrth- (“anti-”) +‎ mater (“matter”). === Noun === gwrthfater m (uncountable) antimatter ==== Derived terms ==== gwrthfaterol (“relating to antimatter, antimaterial”) === Mutation === === Further reading === Griffiths, Bruce; Glyn Jones, Dafydd (1995), “antimatter”, in Geiriadur yr Academi: The Welsh Academy English–Welsh Dictionary‎[1], Cardiff: University of Wales Press, →ISBN