This is the 1636th most frequent Japanese word.
満ち
"満ち" (michi) means "to be full" or "to be filled."
Here, '満ち' (michi) is used to describe the sea 'filling' or 'rising up' due to tidal changes.
海は満ちて波が高くなった。
The sea rose, and the waves became higher.
In this example, '満ち' conveys the feeling of being 'full of' or 'imbued with' a certain emotion.
彼女の表情には喜びが満ちていた。
Her expression was filled with joy.
This usage represents '満ち' as pertaining to the moon 'becoming full' or 'waxing' to completion.