Beloved and One and only

Beloved noun - A person with whom one is in love.

One and only and beloved are semantically related in someone adored topic. In some cases you can use "One and only" instead a noun "Beloved".

One and only adjective - Eminent beyond or above comparison.

Beloved and one and only are semantically related in love topic. Sometimes you can use "Beloved" instead a noun phrase "One and only", if it concerns topics such as sweetheart, darling, dear, person whom another loves.