The ignorance entrenchment. Ignorance as something innate and deeply embedded in the consciousness, which is difficult to remove, and which serves as the basis for the production of afflictions (avidyāvāsa bhūmi). Discussed at length in the Śrīmālā-sūtra, the Sutra of Original Karma, and Wŏnhyo's Doctrine of the Two Hindrances.

The fifth of the five 住地, i.e. the fundamental, unenlightened condition; the source or nucleus of ignorance; also ignorance as to the nature of things, i.e. of their fundamental unreality.

A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous

avidyā-vāsa-bhūmi.

佛教漢梵大辭典

P2153