filu adj.(u) much, many. [Pgmc felu < IE pelu]
This adjective is fairly irregular. There is no distinction for gender: only for case, and the declension follows the paradigm of strong u-stem nouns. It was never used in the plural. There is no comparative or superlative (though the suppletion of mikils may be used). The genitive declension could be used as an adjective to imply “very” or “quite,” or the nominative form filu- could be prefixed directly onto a word to convey the same connotation.