General Synonyms:
* Dodging
* Shifty
* Ambiguous
* Vague
* Indirect
* Unclear
* Noncommittal
* Deceptive
* Tricky
Synonyms emphasizing avoidance:
* Elusiveness
* Slippery
* Elusive
* Escaping
* Sidestepping
Synonyms emphasizing deception:
* Misleading
* Dishonest
* Devious
* Cunning
* Sly
Synonyms emphasizing lack of clarity:
* Obscure
* Unforthcoming
* Cryptic
* Mysterious
The best synonym for "evasive" will depend on the context of your sentence.