Amvujāla (Amvujala) is one of the names of God Śiva (Siva) mentioned in Śivasahasranāmastotra (Sivasahasranamastotra; The Hymn of Thousand Names of God Siva). Nīlakaṇṭha (Nilakantha), the commentator has defined the meaning of the name as follows —
amvujālaḥ jalasamūhaḥ sāgara ityarthaḥ.
Amvu means water. By ‘water’, Nīlakaṇṭha (Nilakantha) speaks of the ocean-like manifestation of God Śiva, and at the same time, amvu or water is also one of the Pañcabhūta (Panchabhuta) or five great elements. The entire world is made of these elements –Kṣiti (Kshiti; Soil), Ap (Water), Teja (Fire or Energy), Marut(Wind) and Vyoma (Ether). God Śiva is conceptualised as possessing the quality of amvu or water, so He is referred to as Amvujāla.

In Vāyupurāṇa (Vayupurana), it is said that God Brahmā (Brahma) gave eight names to Śiva , such as Bhava, Īśa and the like. These eight names have eight forms. Another name of Bhava is Apa. God Rudra-Śiva manifests himself as water, in this form — tadviveśa tatastoyaṃ tasmādāpo bhavaḥ smṛtah.

In the beginning of Creation, emerged water. So, water was the initial creation of the Supreme Power — āpo eva sasarjādau — and Mahādeva is also Ādideva (Adideva, the Primary and the foremost God), So in Purāṇa(s), He has been identified with water. Thus He is known as both Āpa and Amvujāla.