Step 1: Understanding the Concept:
The question asks for the term used to describe 'fast' tempo ('laya') in the Carnatic music system.
Step 2: Detailed Explanation:
In both Carnatic and Hindustani music, the tempo is categorized into three main speeds ('kaala' or 'laya'):
- Vilamba Laya: Slow tempo.
- Madhya Laya: Medium tempo.
- Druta Laya: Fast tempo.
'Ati Vilamba' would mean 'very slow', which is a sub-category of Vilamba. The primary term for fast tempo is Druta.
Step 3: Final Answer:
Druta laya is the term for fast tempo in the Carnatic Tala system.