The affix ṣṭarac expresses slenderness after the words 1. vatsa 2. ukṣan 3. aśva and 4. ṛṣava,
The anuvritti of हृस्व ceases. Thus वत्सतरः 'a weaned calf' becoming slender in reaching the second period of its age. उक्षतरः 'a slender bull': being the third age of a वत्स ॥ अश्वतरः 'a mule': (तस्य तनुत्वमन्यपितृकता); वृषभतरः 'a slender bull or that cannot draw the load'.,