resister
re·sis·ter
noun
1.
someone who systematically obstructs some action that others want to take
2.
someone who offers opposition
Origin
From resist + -er.
Related words
Narrower terms
WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). WordNet 2.1 Copyright Princeton University. All rights reserved. Wiktionary content is available under the Creative Commons Attribution-ShareAlike Licence.