1. noun /əˈtæk/
a) An attempt to cause damage or injury to, or to somehow detract from the worth or credibility of, a person, position, idea, object, or thing, by physical, verbal, emotional, or other assault.
See Also: attachment
2. verb /əˈtæk/
b) To aggressively challenge a person, idea, etc., with words (particularly in newspaper headlines, because it typesets into less space than "criticize" or similar).
Wikipedia foundation.