Synonyms for "Support"
General:
* Assist
* Aid
* Back
* Boost
* Encourage
* Help
* Maintain
* Sustain
* Uphold
* Strengthen
* Bolster
* Promote
* Advocate
* Champion
Specific:
* Underpin (to provide a firm basis for)
* Prop up (to keep something from falling)
* Shoulder (to take on responsibility)
* Stand by (to remain loyal to)
* Root for (to encourage someone)
* Champion (to defend or advocate for)
* Validate (to confirm the worth or truth of)
Figurative:
* Stand with (to show solidarity)
* Be there for (to provide emotional support)
* Lean on (to rely on for help)
Negative:
* Abet (to assist someone in doing wrong)
* Condone (to tolerate or accept something wrong)
The best synonym for "support" will depend on the context in which it is used. For example, if you are talking about providing financial support, "assist" or "aid" might be more appropriate. If you are talking about emotional support, "be there for" or "lean on" might be better choices.
I hope this helps!