The term 'antisocial one' can be described by the crossword solutions of 'LONER' (5 letters), 'LONERS' (6 letters), and 'NERD' (4 letters). A LONER is someone who prefers to be alone and avoids social interaction, while LONERS is the plural form of the same word. A NERD is someone who is socially awkward and often has an intense interest in a particular subject. All three words describe someone who is not very sociable and may prefer to be alone.