leak, escape
洩 centers on something contained escaping or being released: leaking out, seeping away, or slipping free.
洩 combines the water radical 氵 with 曳, which likely contributes the sound and the idea of pulling or dragging. The exact historical development is uncertain, but the character suggests water being drawn out or escaping.
Water 氵 is being pulled or dragged 曳 away, like a slow leak from a container. Picture a bucket with a small crack where water escapes drop by drop.
For エイ, imagine a leaky pipe making a long 'A' sound as water escapes: 'A' -> エイ, and the water keeps leaking out.
leak (of secrets, information, etc.); disclosure; divulging
information leak; data breach
leak of official secrets; leaking of confidential information
leakage current
leaking of a secret; leakage of a secret
(crime of) revealing state secrets; charge of revealing national security information
sunlight sifting through the tree leaves
disclosure (leakage, betrayal) of military secrets