1trace 
/ˈtreɪs/ noun
plural trac·es /ˈtreɪs/ noun [count] 1 : a very small amount of something
▪ He could detect a trace [=hint] of cinnamon in the cookies. ▪ She spoke without a trace of irony. — sometimes used before another noun ▪ Trace amounts of the pesticide were found in many foods. — see also trace element 2 : something (such as a mark or an object) which shows that someone or something was in a particular place
▪ The scientists found traces of human activity in the area. ▪ The thieves left no trace of evidence behind. ▪ He disappeared/vanished without a trace. [=without leaving any signs to show where he went] 3 technical : a line drawn by a machine to record how something (such as a heartbeat or an earthquake) changes or happens over time
▪ He could detect a trace [=hint] of cinnamon in the cookies. ▪ She spoke without a trace of irony. — sometimes used before another noun ▪ Trace amounts of the pesticide were found in many foods. — see also trace element
▪ The scientists found traces of human activity in the area. ▪ The thieves left no trace of evidence behind. ▪ He disappeared/vanished without a trace. [=without leaving any signs to show where he went]
