As a Verb or Adjective: 1. Of more than one thing or person, to be only one and not more of its kind; to be on its own and separate from other things. English = (be) single, (be) lone, (be) alone, (be) unaccompanied. 2. Of people in a group, to be not married. English = (be) single. As Modifier: 1. Used next to a verb sign to mean the action is done by each of several people on its own and separately from other actions. English = singly, only, alone. 2. Used next to a verb sign to mean the action is done by only one person separately from other people and without any help. English = alone, individually. 3. In mathematics, used alone or next to the sign for VARIABLE to mean ‘independent variable’. An independent variable (often represented by x) varies in a way which does not depend on that of another variable. English = independent variable.