Answer:
Considering it's prefix, syntax and context, indeterminate means Overwhelming.
Step-by-step explanation:
The following excerpt is taken from "The Garden of Forking Paths"
"...........The publication was senseless. The book is an indeterminate heap of contradictory drafts. I examined it once: in the third chapter the hero dies, in the fourth he is alive........."
Usually the word indeterminate means something that is not exactly known or defined. A thing that is vague and not clear is called indeterminate. However, in this excerpt, it means Overwhelming, which means it is so great that it cannot be determined.