Literally the word means ‘reciting’ (the Vedas) ‘after’ or ‘following’ the teacher. Hence it refers to the recitation of the Vedas in general. However, it is used in a more technical sense, to indicate a division of the Vedic mantras.
The Ṛgveda Saṁhitā, the basic scripture of Hinduism, is divided into ten books each of which is called ‘maṇḍala.’ Each maṇḍala is again divided into several subsections called anuvākas. The anuvākas are further subdivided into sūktas, each sūkta containing one or more ṛks (verses). There are 85 anuvākas in the Ṛgveda.
Śaunaka has prepared an index for these anuvākas, known as Anuvākānu-kramaṇī.