hold aloft
翳 centers on holding something aloft, often with the sense of shading or covering from above. The given meaning 'hold aloft' is the primary idea; related senses of shadow or cloudiness are natural extensions of something held up to block light.
翳 combines 殹 (a phonetic component with an arrow-like shape) and 羽 (feathers/wings), suggesting something held up like a feathered screen or canopy. The exact historical development is uncertain, but the character is associated with shading or holding aloft.
Picture a feathered canopy (羽) held aloft by a sturdy frame (殹). The feathers are spread wide, shading everything beneath them.
For エイ, imagine holding aloft a large feathered fan and saying 'A!' (like 'eh') in admiration: 'A' -> エイ, as you lift the shade.
to hold up over one's head; to hold aloft
degenerative eye disorder caused by cloudiness in front of the pupil
makeshift hunting blind; waiting in a makeshift hunting blind
to shade one's eyes with one's hand (blocking sunlight, looking afar, etc.)
large fan-shaped object held by an attendant and used to conceal the face of a noble, etc.
glaucoma