Noun
caer (plural caers)
A Welsh fortress.
Caer is Welsh for fort and -dyf is in effect a form of Taf (Taff), the river which flows by Cardiff Castle, with the t showing consonant mutation to d and the vowel showing affection as a result of a (lost) genitive case ending. Source: Internet
He further suggested that Cavalon/Camelot became Arthur's capital due to confusion with Arthur's other traditional court at Carlion (Caer Lleon in Welsh). Source: Internet
It was very easy business,” Caer says. Source: Internet