Gosh-darned is a slang term used to express mild annoyance or frustration. Some synonyms for gosh-darned include darn, darned, dratted, frustrating, irritating, annoying, vexing, bothersome, pesky, and aggravating. Darn is the most commonly used synonym for gosh-darned and is often used to replace curse words in polite conversation. Some more intense synonyms for gosh-darned include cursed, damned, and blasted, which are more suitable for expressing intense frustration. Ultimately, the choice of synonym depends on the level of frustration being felt and the level of politeness required in the conversation.