n.
Function: adjective
Etymology: Middle English, alone, from Anglo-French sul, soul, seul, from Latin solus
Date: 14th century
1 : not married ― used chiefly of women
2 archaic : having no companion : SOLITARY
3 a : having no sharer b : being the only one <she was her mother's sole support>
4 : functioning independently and without assistance or interference <let conscience be the sole judge>
5 : belonging exclusively or otherwise limited to one usually specified individual, unit, or group
– sole · ness \ ' s ō l-n ə s \ noun