caus·a·tive 
/ˈkɑ:zətɪv/ adjective
/ˈkɑ:zətɪv/ adjective formal : making something happen or exist : causing something
▪ A virus was found to be the causative agent of smallpox. ▪ Speed was a causative factor in the accident. [=speed helped to cause the accident]
▪ A virus was found to be the causative agent of smallpox. ▪ Speed was a causative factor in the accident. [=speed helped to cause the accident]
