1. forming adjectives
a. full of, characterized by, having
⇒ joyful, painful
b. having the qualities of
2. forming nouns the quantity that fills or would fill, the plural is formed by adding -s to the resulting word [teaspoonfuls, handfuls] or, sometimes, by adding -s- between the noun stem and the suffix [cupsful]
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.