is it ok for an American to use the greeting "nameste?" when meeting someone from India?

Not a good idea to mention any greeting, if you don't understand what it means, in any language. It's Hindu BTW.

This one has a special meaning.

Namaste: the light in me, sees the light in you.

I personally would wait until they said Namaste

check it out on google first idk

You say it at the end of yoga

I always say 'Namaste', and I usually get a smile for my efforts.

Hahahahah