The word 挺拔 is formed by combining the character 挺, which means straight or erect, with 拔, which means to pull out or to rise high. Together, they create a compound word where 挺 emphasizes uprightness and firmness, while 拔 adds the notion of towering or standing out, resulting in a meaning that describes something tall, straight, and imposing, such as a tree or posture.