mindmap root((缺少)) lack may imply either an absence or a shortage in supply: a club that ~s a room to meet in. want adds to lack the implication of needing or desiring urgently: you may have whatever you ~. need stresses urgent necessity more than absence or shortage: everyone ~s a friend. require is often interchangeable with need but it may heighten the implication of urgent necessity: a situation that ~d drastic measures.