Apri (āprī) in Sanskrit means "conciliation, propitiation" and refers to special invocations spoken previous to the offering of oblations. RV 1.13 is known as the Apri-hymn of the Kanvas, and Sayana in the context of this hymn enumerates twelve Apris propitiating twelve deities, also known as Apris (āpryas). These are deified objects belonging to the fire sacrifice of Vedic religion, the fuel, the sacred grass, the enclosure, etc. The Apris are all regarded as different manifestations of Agni.
The identification of individual Rigvedic verses as "Apris" (f. pl. either Āpríyas or Āpryas) is found in Shrauta Sutra literature. The āśvalāyana-śrauta-sūtra (3.2.5ff) states that these hymns are chosen differently in different schools. Thus, RV 5.28.1 is the Apri of the śaunaka school, RV 7.2.1 in that of vasaiṣṭha, and RV 10.110.1 that of others. Gargya Narayana later gives ten entire Rigvedic hymns (suktas) as "Āprīsūktas" belonging to different gotras.
Aprisuktas
Of the ten Aprisuktas mentioned in Gargya Narayana's commentary, I.13 and I.142 both invoke the Narāśaṁsa and Tanūnapāt manifestations of Agni, I.188, III.4, IX.5 and X.110 invoke only the Tanūnapāt manifestation and II.3, V.5, VII.2 and X.70 invoke only the Narāśaṁsa manifestation.