तृन्

The affix तृन् comes after all verbs in the sense of 'agents having such a habit etc.'.
The न् of तृन् is indicatory, and regulates the accent 6.1.197. As कृ + तृन् = कर्तृ, Ist sing. कर्ता. This affix denotes habit in the following; as, कर्ता कटान् 'who is accustomed to make mats'. Nature:- as, मुण्डयितारः श्राविष्ठायना भवति वधूमूढाम् 'the family of Sravishtayana shave the heads of their widows'; अन्नमपहर्तार आह्वरका भवन्ति श्राद्धे सिद्धे 'the Ahvarakas steal away food as soon as Sraddha is accomplished'; उन्नेतारस्तौल्वलायना भवन्ति पुत्रे जाते 'the Taulvalayanas become elated on the birth of a son'. Skill:- as, कर्त्ता कटम् 'skilful maker of mats'. गन्ताऽऽखेटम् 'skilful hunter'.

Vart:- The simple verbs, without upasargas, take the affix तृन्, when the words so formed are names of sacrificial priests. As हु + तृन् = होतृ, Ist. sing. होता 'the Hotri priest'; so also पोतृ 'the Potri priest'.

Why do we say 'when not taking the upasargas'? Observe उद्गातृ 'the Udgatri priest'; प्रतिहर्तृ 'the Pratihartri priest'. Here the affix is तृच्. Though the form is the same, there is difference however in the accent; i.e. तृन् places udatta accent on the first syllable 6.1.197, while तृच् places it on the last 6.1.163.

Vart:- The augment षुक् is added when नी takes the affix तृन्; as नी + षुक् + तृन् = नेष्टृ, Ist. sing. नेष्टा 'the Neshtri priest'.

Vart:- When signifying diety, the verb त्विष् takes तृन्; the letter अ is the substitute for the इ of the root; and the affix does not take the intermediate इट् augment; as, त्विष् + तृन् = त्वष्टृ, Ist. sing. त्वष्टा 'Tvashtri'.

Vart:- The root क्षद takes तृन्, when the word to be formed means an officer; as क्षतृ 'an attendant, a door-keeper'.

Vart:- In the Veda, the root क्षद takes तृच्, as क्षतृ. The form is the same as the last, but there is difference of accent.