dislike, be weary of, explain
斁 centers on a negative reaction to something prolonged: growing weary of it, disliking it, or wanting to be done with it. The "explain" sense is a rare, possibly archaic extension that does not clearly connect to the main idea.
斁 combines 睪 (which may relate to spying or looking) with 攵 (a hand holding a stick, suggesting an action). The exact historical development is uncertain, but the character likely expressed a sense of weariness or aversion through this combination.
The left side 睪 looks like a watchful eye under a cover, and the right side 攵 is a hand with a stick. Imagine being forced to keep watch for so long that you grow weary and dislike the task.
For エキ, picture a weary person at an eki (駅, station) waiting endlessly for a train that never comes: eki -> エキ, and the long wait makes them dislike the whole journey.