This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. One who deviates from accepted beliefs or policies, especially from a prescribed form of Communism.

n. an ideological defector from the party line (especially from orthodox communism)

"The Islamist party's Selangor leader Datuk Hassan Ali has been at the forefront in policing what he called deviationist movements like the Ahmadiyah and stopping the sale of alcohol in Muslim-majority areas."

defector    deserter   

deviationism   

deviation