In Śrī Vaiṣṇava theological vocabulary, the term uttāraka means 'one who causes the crossing-over' — who ferries the soul across the ocean of saṃsāra to liberation. When combined with āchāryan, it designates a specific mode of the guru's role: not the passive Āchārya who waits for the disciple to come with readiness, but the proactive, compassion-driven Āchārya who recognizes a soul's potential for liberation, goes out to that soul wherever it is, and through sustained love and strategy brings it to the feet of Bhagavān.
Piḷḷai Lokācārya develops this concept in Śrīvacana Bhūṣaṇam in the context of the guru's responsibility. The ordinary understanding is that the disciple seeks the Āchārya. But the uttāraka āchāryan inverts this: moved by dayā (compassion) and by the consciousness that Bhagavān Himself desires every soul's liberation, the Āchārya takes upon himself the burden of reaching out to souls who have not yet sought him. The paradigmatic exemplar is Maṇakkāl Nambi, who — knowing that Āḷavandhār (Nāthamunigaḷ's grandson and the rightful heir of the lineage) had drifted into the life of a court debater — went to him, served in his household for months, patiently established a relationship, and at the decisive moment revealed the lineage and the path. This act of utter self-effacement in service of another's liberation is held up as the supreme expression of ācārya kaiṅkarya and uttāraka grace.
The concept also has an important bearing on the doctrine of paragata svīkāram: just as Bhagavān takes the initiative in accepting the surrendered soul (as exemplified by Rāma's acceptance of Vibhīṣaṇa), the uttāraka āchāryan takes the initiative in going toward the wayward disciple. The Āchārya is understood to be Bhagavān's instrument, and his outgoing compassion is nothing other than Bhagavān's own grace operating through a human vessel.