Amun(-Ra) — the Hidden God
A god whose very name means 'the Hidden One' — too transcendent for even other gods to see.
Also: Amun · Amon · Amen · Amun-Ra · Amun-Re · Imen · Karnak · the Hidden One
Egyptians of the New Kingdom exalted Amun, whose name means 'the Hidden One,' to the head of the pantheon. Merged with the sun god as Amun-Ra, 'King of the Gods,' he was worshipped at the vast temple of Karnak in Thebes. In the later (Ramesside) period theologians described him as hidden even from the other gods — a single concealed power manifest in many forms — a way of thinking some scholars (notably Assmann) read as a move toward transcendence, though that reading is interpretive.
In short
Amun of Thebes — whose name means 'the Hidden One' — who rose to become the preeminent state god of the New Kingdom, fused with the sun god as Amun-Ra and, in Ramesside theology, articulated as a transcendent, concealed deity behind all others.
Where it’s found
New Kingdom hymns to Amun (e.g. the great Leiden hymns, Ramesside); Karnak temple texts
How the idea developed across Egypt
A minor Theban god in the Middle Kingdom; raised to imperial state god in the New Kingdom (Dyn. 18 onward) as Amun-Ra of Karnak; eclipsed under Akhenaten and restored after; the developed 'hidden/transcendent' theology belongs specifically to the later Ramesside hymns (a late-NK development), not to Amun from the start.
Treated as a theological concept (the hidden/transcendent god), not a person. The 'transcendent/concealed' reading is scoped to Ramesside theology and is interpretive (Assmann) — label it as such, not as Amun's character throughout.