Attributively is the adverb from attributive. It tells you that a word is being used in that front-of-the-noun way, doing describing work rather than standing as the main thing named. Teachers say kitchen is used attributively in kitchen table: kitchen is not the table, it only tells you what kind of table. Same idea as attributive, but it answers how is it used? rather than what kind of word is this? You will meet it almost only in grammar notes.