dau ddeg un

== Welsh == === Etymology === From dau (“two”) +‎ deg (“ten”) +‎ un (“one”). === Pronunciation === (North Wales) IPA(key): /ˌdaɨ̯ðɛɡ ˈɨːn/ (South Wales) IPA(key): /ˌdai̯ðɛɡ ˈiːn/ === Numeral === dau ddeg un (cardinal number, decimal) twenty-one Synonym: un ar hugain === Mutation ===