This is the 1796th most frequent Swedish word.
fyllda
"Fyllda" means "filled" in English.
Here, 'fyllda' is metaphorically used as a participial adjective to express days being occupied or imbued with joy, hence indirectly 'filled' with happiness.
Hans dagar var fyllda med glädje.
His days were filled with joy.
Here, 'fyllda' is used as an adjective describing peppers that have been filled or stuffed with something, typically food fillings.
Vi åt fyllda paprikor till middag.
We ate stuffed peppers for dinner.
In this sentence, 'fyllda' serves as a past participle form indicating that the basket is in a state of having been filled with apples.