Formal:
* Sustained applause: This emphasizes the continuous nature of the applause.
* Protracted applause: Similar to sustained, but implies a longer duration.
* Thunderous applause: This highlights the volume and intensity of the applause.
* Standing ovation: This indicates that the audience has risen to their feet to applaud.
Informal:
* Rousing applause: This suggests enthusiasm and excitement.
* Deafening applause: This emphasizes the loudness and intensity of the applause.
* A standing ovation: This emphasizes the audience's respect and admiration.
* A round of applause: This refers to a single period of clapping, but can be used to describe prolonged applause if you use a modifier like "long" or "extended".
Figurative:
* A wave of applause: This creates a sense of movement and energy.
* A crescendo of applause: This suggests that the applause gradually became louder and more intense.
* A chorus of applause: This highlights the unity and enthusiasm of the audience.
The best word will depend on the specific context and the emotion you want to convey.