advance notification (usually written) of the intention to withdraw from an arrangement of contract; "we received a notice to vacate the premises"; "he gave notice two months before he moved"
discover or determine the existence, presence, or fact of; "She detected high levels of lead in her drinking water"; "We found traces of lead in the paint"
express recognition of the presence or existence of, or acquaintance with; "He never acknowledges his colleagues when they run into him in the hallway"; "She acknowledged his complement with a smile"; "it is important to acknowledge the work of others in one's own writing"