Our Divine Lady
EmperumāṭṭI (Tamil: em = our + perumāṭṭI = great lady/mistress; 'our great lady' / 'our empress') is the Tamil honorific for Śrī Devī — Lakṣmī — expressing the community's intimate and dependent relationship with Her as their queen and mother.
Inseparable from EmberumāṆ
Just as emberumāṉ ('our Lord') expresses the devotee's belonging to Bhagavān Nārāyaṇa, emperumāṭṭI expresses belonging to His inseparable consort Śrī Devī. The Śrī Vaiṣṇava tradition always honors Bhagavān with His consort — taking refuge in Śrīman Nārāyaṇa specifically means taking refuge in Śrī-pati, 'the Lord of Śrī.'
Puruṣakāra Role
EmperumāṭṭI as puruṣakāra (the recommended) intercedes for devotees who approach Bhagavān for liberation. Her infinite compassion overcomes the barriers that a soul's faults might otherwise create. Śrī Raṅganāyakī (the Tāyār of Śrī Raṅgam) is the supreme manifestation of EmperumāṭṭI in the temple tradition.