unit of electrical power, 1882, in honor of James Watt (1736-1819), Scottish engineer and inventor. The surname is from an old pet form of Walter and also is in Watson.
-age
word-forming element in nouns of act, process, function, condition, from Old French and French -age, from Late Latin -aticum "belonging to, related to," originally neuter adjectival suffix, from PIE *-at- (source of Latin -atus, past participle suffix of verbs of the first conjugation) + *-(i)ko-, secondary suffix forming adjectives (see -ic).