Final answer:
The dance style described with strict vocabulary of movement and a dignified attitude is Ballet, which is a highly technical form of dance with a traditional set of structured steps and movements.
Step-by-step explanation:
The style of dance that is known for having a strict vocabulary of movement, including a turned-out position, a rigid spine, great elevation, and a dignified attitude with relaxed hand positions, is Ballet. Ballet is an artistic dance form that requires precision and often involves a traditional set of structured steps, postures, and movements which have been passed down through generations. It is associated with grace, flexibility, strength, and technique. The posture and strict technique such as turnout of the legs and pointed feet, are fundamental characteristics that differentiate ballet from other dance styles.