[ 3 syll. cai-nan, ca-in-an ] The baby boy name Cainan is pronounced as Key-AY-NahN or KEY-NahN (English) â . Cainan is largely used in the English language and its origin is Hebrew. Cainan is a variant transcription of the name Kenan (English). Cainan is rarely used as a baby name for boys. It is not listed in the top 1000 names.