What does the prefix 'not' signify in words?

The prefix 'not' signifies the concept of reversal or negation when it is used in words. This means that when 'not' is added to a term, it transforms the meaning of that word into its opposite. For instance, when combined with 'enable', it creates 'not enable', which conveys the opposite meaning, effectively representing the negation of the ability to enable something. This characteristic of the prefix makes it a powerful linguistic tool for creating negative forms and modifying the meaning of words in the English language.

In contrast, the other options do not accurately reflect the function of the prefix 'not'. While some prefixes may denote marking or leading, or relate to thought, 'not' specifically serves to reverse or negate a given word's meaning.