First, I'm not familiar with the idiom hedging one's bets. What does it mean?
Second, while it is true that 'in any given sentence, a word can only, if it is not repeated, be one part of speech', every words has a a form. When we talk about words within a sentence, we talk about their function: how their position within the structure contributes meaning; e.g., John laughed. John is a noun in form, specifically, a proper noun, and its function is that of subject.
Third, a noun can indeed 'function' an adjective; e.g., mountain bike (Learn more here). On the term 'determiner':
Note, terminology has always been and always will be a problem--for linguists and learners alike. My seasoned advice, don't get caught up in the semantics of it all, at least, not just yet. Learn the basics, first. It's good advice. (I've been teaching English for over 20 years, in 4 countries, and I hold an MA in Theoretical Linguistics.)
What are traditionally and popularly, if mistakenly, called possessive adjectives
— in linguistic analyses possessive pronouns
, possessive determiners
or genitive pronouns
— are a part of speech
that prototypically modifies a noun
by attributing possession to someone or something (but see below
). Depending on the theory the grammar subscribes to, English
"possessive adjectives" are determiners
: possessive determiners, possessive pronouns, dependent genitive pronouns, weak possessive pronouns,
and so forth.
Read more here Possessive adjective - Wikipedia, the free encyclopedia
Hope my advice helps.