tenuous
TEN-yoo-usadjMeaning very weak, thin or slight
Memory hook TENT-uous: a TENT barely standing. The tent is held up by one thin, wobbly pole, and the next breeze could knock it down: its hold is tenuous.
The kitten kept a tenuous grip on the top of the curtain.
In context The link between the two thefts was tenuous, resting only on the fact that both happened on a Tuesday, so the detective kept looking for stronger evidence.
Similar flimsy, weak, slight, thin
Opposite strong, solid, substantial
From Latin tenuis, “thin.”