Tenuous
/ˈtɛnjuəs/ adjective mediumSo thin, weak, or flimsy that it could easily fail or break under pressure.
The prosecution's case rested on a tenuous link between the defendant and the crime scene.
Memory Trick
Tenuous comes from Latin 'tenuis,' meaning thin -- picture a tenuous argument as a spider's thread, delicate enough to snap the moment real weight is placed on it.