This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 歝 is uncertain. It visually combines 睪 and 欠, but the original semantic and phonetic roles are unclear.
With no clear meaning, picture the left side 睪 as a mysterious container and the right side 欠 as a person yawning or lacking something. Together they suggest an unknown action or state.
For エキ, imagine a person yawning (欠) while holding a mysterious container (睪) and saying 'eh key' (エキ) as they try to open it.