Use the adjective stubborn to describe someone who is not open to new ideas or ways of doing things, like your uncle who refuses to listen to any music made after 1990. Stubborn is the opposite of flexible. stubborn definition: unwilling to change opinion or behavior. Check meanings, examples, usage tips, pronunciation, domains, and related words. Discover expressions like " stubborn as a mule", " stubborn streak", " stubborn as mules". Stubborn definition: unreasonably obstinate; obstinately unmoving.. See examples of STUBBORN used in a sentence. Learn the meaning of stubborn as an adjective, and find out its synonyms, antonyms, and related words. Compare different dictionaries and translations of stubborn in English and Spanish.