General synonyms:
* Different
* Another
* Alternative
* Distinct
* Separate
* Diverse
* Varying
* Remaining
* Else
* Besides
More specific synonyms:
* Additional: (when referring to something extra)
* Further: (when referring to something beyond what has already been mentioned)
* Remaining: (when referring to what is left)
* Contrary: (when referring to something opposite)
* Conversely: (when referring to something in contrast)
Formal synonyms:
* Alternate
* Supplementary
The best synonym to use will depend on the specific meaning you want to convey.