delay: usually implies a putting off (as a beginning or departure): a tight schedule means we cannot ~ any longer.


procrastinate: implies blameworthy delay especially through laziness, hesitation, or apathy: ~s about making every decision.


lag: implies failure to maintain a speed or rate set by others: we ~ behind other countries in shoe production.      (rate泛指指标)


loiter: implies delay while in progress, especially in walking: ~ed at several store windows before going to church.     (这里progress表示行动不是进步)


dawdle: more clearly suggests idleness, aimlessness, or a warndering mind: children ~ing on their way home from school.


dally: suggests delay through trifling or vacillation when promptness is necessary: stop ~ing and get to work.      (trifle注意力不集中)     (vaccilate犹豫:摇摆反复)  


delay: 泛指拖后延迟 (如开始、出发)，procrastinate: 应受指责的拖延，由于懒惰犹豫漠视，lag: 没有跟上他人的速度指标，loiter: 行动的过程中拖延，特别是行走时，dawdle: 更明确表示空闲漫游无目的，dally: 表示在需要快速的时候磨蹭或犹豫


记忆方法: 1) 首字母联想PD LDLD浦东溜达溜达<==拖延了时间

               2) 拖延的意思是出发或行动缓慢导致落后mean to move or act slowly so as to fall behind.首字母联想PD LDLD浦东溜达溜达<==拖延了时间