bullfighter, copywriter, firefighter, firelighter, lamplighter, screenwriter, scriptwriter, songwriter, speechwriter, sportswriter, typewriter.
Your query has returned 315 words, which include anagrams of underwriter as well as other shorter words that can be made using the letters included in underwriter.
The words in this list can be used in games such as Scrabble, Words with Friends, Wordscapes and other similar games.