a disloyal person who betrays or deserts his cause or religion or political party or friend etc.
source: WordNet 3.0
a person who abandons their duty (as on a military post)
source: WordNet 3.0
One who forsakes a duty, a cause or a party, a friend, or any one to whom he owes service; especially, a soldier or a seaman who abandons the service without leave; one guilty of desertion.
