The affix śatṛ comes after the verb su 'to press out or extract juice' when the sense is that of association with sacrifice.,
The word यज्ञसंयोग is an instrumental compound, meaning association or connection (संयोग) with sacrifice. As सु + नु + शतृ (III. I. 76), 3.4.113 = सुनु+ अत् (I. 2. 4.) = सुन्वत् (VI. I. 77), Ist. sing. सुन्वन्, Ist. pl. सुन्वन्तः 'the sacrificers'; as in सर्वे सुन्वन्तः 'all are interested in, or partake of, or share in the sacrifice'.
The word संयोग indicates that the principal sacrificer. i.e. the यजमान is meant and not every person who is associated in the performance of a sacrifice in a subordinate capacity; such as याजकाः 'the sacrificing priests'.
When connection with sacrifice is not meant we have the सुनोति सुराम् 'he distils liquor'.,