It's pronounced like "nah" and is the direct ancestor of the modern English word "nay".
Here are some other Old English words that can be used to express negation:
* "ne" (pronounced "neh") - This is a more general negation particle, similar to "not" in modern English.
* "nāwiht" (pronounced "nah-wiht") - This means "nothing" or "not at all".
* "nān" (pronounced "nahn") - This means "none".
These words were often combined with other words to form more complex negations. For example, "ne mæg" means "cannot" and "nāwiht hæfþ" means "has nothing".