Usage of "tenebrous" [closed]
"Tenebrous" mostly means obscurity or darkness. Thus it implies lack of clarity of expression.
On the other hand, "ambiguous" usually indicates the presence of two or more meanings.
To answer your question, yes, "tenebrous" can be used instead, but it wouldn't be very accurate.
MW offers as one of the definitions of tenebrous:
hard to understand: obscure
I find the metaphorical reference to darkness appealing.