station
驛 centers on a station: a fixed stopping point along a route, originally for changing horses or resting during travel.
驛 is the traditional form of 駅. It combines 馬 (horse) with 睪, which likely contributed the sound and relates to a relay or change, reflecting the historical use of stations for changing horses.
The left side is a horse 馬, and the right side 睪 suggests a relay or change. Picture a station where tired horses are swapped for fresh ones along a long journey.
For エキ, imagine an energetic horse at the station: the first part of 'energetic' sounds like エキ, and the horse is ready to go.
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