a To a greater degree or extent. (defdate|from 10th c.)
a (context|now|_|poetic) In negative constructions: any further, any longer; any more. (defdate|from 10th c.)
a (senseid|en|used to form the comparative) Used alone to form the comparative form of adjectives and adverbs. (defdate|from 13th c.)
a (context|now|_|dialectal|_|or|_|humorous) Used in addition to an inflected comparative form. (Standard until the 18th century.) (defdate|from 13th c.)