There can be many different words that could be used as synonyms for the phrase "stubborn stump." A few possibilities might include unyielding stump, steadfast stump, tenacious stump, obstinate stump, or intractable stump. Each of these words conveys a sense of persistence or stubbornness, indicating that the stump is unwilling to give way or be removed easily. Other potential synonyms could include immovable, unshakeable, or resolute, all of which would contribute to the overall impression of the stump as a difficult obstacle to overcome. Ultimately, the choice of synonym will depend on the specific context in which the term is being used.