Meaning : In place of, or as an alternative to.
Example :
Felix became a herpetologist instead.
Alternatively we could buy a used car.
Synonyms : alternatively, or else
Meaning : On the contrary.
Example :
Rather than disappoint the children, he did two quick tricks before he left.
He didn't call; rather (or instead), he wrote her a letter.
Used English terms instead of Latin ones.
Synonyms : rather