This is the 5507th most frequent Korean word.
먹은
"먹은" means "ate" or "eaten."
The word '먹은' is used here as a descriptive past modifier, modifying the noun '음식' (food), meaning 'food that I ate'.
어제 먹은 음식이 정말 맛있었어요.
The food (that) I ate yesterday was really delicious.
The word '먹은' is part of the phrase '먹은 후에' where it describes a completed action, specifically 'eating,' referencing the act after it is done.
먹은 후에 설거지를 해야 해요.
After eating, we need to do the dishes.
Here, '먹은' modifies the noun '약' (medicine), indicating 'the medicine that I took,' describing the specific instance of taking medication in the context.