नोत्वद्वर्ध्रबिल्वात्

The affix मयट् does not come in the छन्दस् (Vedas) after the disyllabic words having a short vowel उ in them, nor after the words 1. वर्ध्र and 2. बिल्वा।
Thus मौञ्जं शिक्यम् from मुञ्ज by अण् ॥ गार्मुतं चक्रम्, वार्ध्री बालप्रग्रथिता भवति; बैल्वो ब्रह्मवर्चसकामेन कार्यः ॥

The word उत्वत् means 'having उत् or short u 1.1.70' The rule does not apply to words containing long ऊ, as भूममयान्यभ्राणि ॥ The वत् in उत्वत् shows that the rule applies not only to words ending in उ, but also to words having उ. Had वत् not been used, the tadanta-vidhi would require the application of the rule to words ending in उ, but not to those which had उ in any other part of their form. So that the prohibition applies to वेणु also, as वैणवी यष्टिः 4.3.136.

The word मुञ्ज is ady-udatta by तृणधान्यानां (Phit II.4): and therefore it takes the universal अण् 4.3.134. The word गर्मुत् is formed by the affix उत् plus the augment मुट् (मृग्रोरुतिः, ग्रोमुट्च Un I.94 and 95), and is finally acute, and therefore it takes अञ् by 4.3.140, and forms गार्मुत ॥ This word has acute on the final also, as तस्या एतं गार्मुतं चरुं निर्वयेत् ॥ The word वर्ध्र is ady-udatta by Phit II.19. And therefore takes अण्, the feminine being formed by ङीप् 4.1.15.