1) Another option 2) As an alternative 3) Instead 4) Or else 1) Eccentrically 2) Else 3) If not 4) Instead 5) Or 6) Ossia 
• (adv.) In the manner of alternatives, or that admits the choice of one out of two things.
Al·ter'na·tive·ly adverb In the manner of alternatives, or that admits the choice of one out of two things. 
[adv] - in place of, or as an alternative to
alternatively In place of, or as an alternative to: 'Alternatively we could buy a better house.'
as an alternative adverb in place of, or as an alternative to; `Felix became a herpetologist instead`; `alternatively we could buy a used car`