> Thanks so much for this clarification... however I have a further
> question. What would one use to greet a group of women, a group of
men, or
> a mixed group?

A curious mind should always be rewarded with an answer :)

heilir ...to a group of men
heilar ...to a group of women
heil ...to a mixed group

and perhaps least useful, but conceivable,

heilt ...to a "neuter", perhaps an animal or something abstract;
but even then, people identify the animal's gender and
address accordingly

In any case, I've now given the singulars and plurals of the three ON
genders (in the nominative case only), so you should be prepared to
greet anything you meet ;)