One of the one thousand names of Śiva (Shiva). Devī (devi) Aditi is the wife of Prajāpati (Prajapati) Kaśyapa (Kashyapa); she is a mother goddess. Mahādeva (Mahadeva) is the creator of the universe, the begetter/progenitor of gods, and hence he is considered to be a form of Aditi, the maternal figure, and also referred to as Aditi.
Another meaning of the word ‘aditi‘ can be earth (pṛthivī or prithivi). In a great, ancient text such as Śatapatha Brāhmaṇa (Satapatha Brahmana), ‘aditi‘ has been used as a synonym of earth—
iyaṃ vai pṛthivī aditiḥ.
The earth is the mother of all beings, she bears all of life. Because Mahādeva bears all of creation, he is also renowned as Pṛthivī or as a form of Aditi. Therefore, one of his names is Aditi—
aditirdevamātā ‘iyaṃ bā aditi’riti śruteḥ pṛthvī bā (definition by Nīlakaṇṭha or Nilakantha).
Pandit Haridasa Siddhantavagish has provided a fascinating explanation for the word ‘aditi‘ from a somewhat alternative perspective. The word ‘diti‘ comes from the Sanskrit root ‘do‘ which means to break or penetrate. When the inflection ‘—kti‘ is added after the root ‘do‘, the resulting form is diti, meaning one that can be broken or permeated. Mahādeva is the shapeless, indivisible form of brahma, he cannot be broken, nor be permeated or divided; hence he is known as Aditi—
aditiḥ khaṇḍanrahitaḥ ‘do abakhaṇḍane’ iti dodhātoḥ ‘kti’ pratyaye diti rūpam tatonañ samāsaḥ (definition by Bhāratakaumudī or BHaratakaumudi).