Definitions from Wordnet 2.0

• a person who is of equal standing with another in a group
• make equal, uniform, corresponding, or matching; "let''s equalize the duties among all employees in this office"; "The company matched the discount policy of its competitors"
• be identical or equivalent to; "One dollar equals 1,000 rubles these days!"
• be equal to in quality or ability; "Nothing can rival cotton for durability"; "Your performance doesn''t even touch that of your colleagues"; "Her persistence and ambition only matches that of her parents"
• well matched; having the same quantity, value, or measure as another; "on equal terms"; "all men are equal before the law"
• equal in amount or value; "like amounts"; "equivalent amounts"; "the same amount"; "gave one six blows and the other a like number"; "an equal number"; "the same number"

Definitions from Wiktionary

• a person who is of equal standing with another in a group