indicator
https://gyazo.com/acb2616b7d167e38b497803579cea86b
noun
指示する人[物]; 尺度; 〘経〙 経済指標
e.g. car ownership is frequently used as an indicator of affluence.
2. usually with modifier a gauge or meter of a specified kind: 表示計器[装置]; (計器の)指針
e.g. a speed indicator.
〘化〙 指示薬