Someone who flees or runs away from the police to avoid capture is a fugitive. "Authorities were looking for three men who escaped from prison today. Authorities believe the three fugitives may be disguised as nuns and advise the public to be careful."
Although a fugitive can specifically be someone fleeing from the police, the noun can also refer to anyone who is fleeing from an untenable situation. "The family asked for asylum in the United States because they were fugitives from their own oppressive government." As an adjective, the word can mean "fleeing or fleeting." "Many people helped the fugitive slaves to safety." "At night, he was plagued with fugitive thoughts: they seemed important when he woke from sleep, but by morning he had forgotten them."
