मिधः सप्त जिह्वाः' इति मन्त्रवर्णात् ।सप्त अश्वा वाहनान्यस्येति सप्तवाहनः; सप्तनामैकोऽवो वाहनमस्येति वा. 'एकोऽश्वो बहति सप्तनामा' इति श्रुते ।मूर्तिर्घनरूपं धारणसमर्थं चराचरलक्षणम्, 'ताभ्योऽभितप्ताभ्यो मूर्तिरजायत' इति श्रुतेः ; तद्रहित इति अमृर्तिः; अथवा, देहसंस्थानलक्षणा मूर्छितागावयवा मूर्ति, तद्रहितः इति अ मूर्तिः ।अघं दु.खं पापं चास्य न विद्यते इति अनघः ।प्रमात्रादिसाक्षित्वेन सर्वप्रमाणागोचरत्वात् अचिन्त्यः; अ यमीदृश इति विश्वप्रपञ्चविलक्षणत्वेन चिन्तयितुमशक्यत्वात् अचिन्त्यः ।असन्मार्गवर्तिनां भयं करोति, भक्तानां भयं कृन्तति कृणोतीति वा भयकृत् ।वर्णाश्रमाचारवतां भयं नाशयतीति भयनाशनः; 'वर्णाश्रमाचारवता पुरुषेण परः पुमान् ।विष्णुराराध्यते पन्था नान्यस्तत्तोषकारकः' इति पराशरवचनात् ॥
In plain words
Because He has seven horses as His mounts, He is Saptavahana, based on the Shruti: 'A single seven-named horse carries Him.' Since form is the dense structure characterizing the moving and unmoving—as the Shruti states, 'From those heated elements form was born'—He who is free from it is Amurti, the Formless One. Alternatively, since physical embodiment is constituted by bodily limbs, He who is free from this is likewise Amurti. Because neither sin nor sorrow touches Him, He is Anagha. He is Acintya because, as the eternal witness of all knowers, He transcends every standard means of knowledge and cannot be mentally delimited as 'He is like this,' remaining entirely distinct from the phenomenal universe. He is Bhayakrit because He strikes terror into wrongdoers while cutting away the fears of His devotees. He is Bhayanasana because He dispels the dread of those devoted to their rightful duties, as Parashara declares: 'The supreme Purusha Vishnu is propitiated by one who follows the duties of caste and life-stage; this is the path, and there is no other that pleases Him.'
Close to the Sanskrit
From the mantra text 'seven tongues...'; Saptavahana because seven horses are his vehicles, or because a single horse with seven names is his vehicle, from the Shruti 'A single horse named seven carries.' Form is dense shape capable of sustaining, characterized by the mobile and immobile; from the shruti 'From those intensely heated ones, form was born'; devoid of that is Amurti; or, form is bodily arrangement characterized by limbs, devoid of that is Amurti. Agha, grief and sin, does not exist for him, thus Anagha. Because he is the witness of the knowers etc. and is beyond all means of knowledge, Acintya; because he cannot be contemplated as 'this one is thus,' being distinct from the universal manifestation, Acintya. He causes fear to those following wrong paths, and cuts or inflicts fear of devotees, hence Bhayakrit. He destroys the fear of those who follow caste and stage duties; from Parashara's statement: 'By a person observing caste and stage duties, the supreme Purusha Vishnu is worshipped; this is the path, there is no other that pleases Him.'