WordWeb Online

1. At some indefinite or unstated time
   "let's get together sometime"; "everything has to end sometime"; "It was to be printed sometime later"
    
2. [archaic] At a previous time
   - once, formerly, at one time, erstwhile [archaic], erst [archaic]

1. Belonging to some prior time
   - erstwhile, former, old, onetime, one-time, quondam

See also: past

Encyclopedia: Sometime