Juno. She was the wife of Zeus and also his elder sister, the daughter of Cronos and Rhea, and her divine status was that of 'Queen of Heaven'. As often, her name is no doubt pre-Greek, but traditionally there are two main contenders by way of an origin. The first is the meaning 'lady', with her name being a feminine form oiheros, 'hero', 'warrior'.
The second is a derivation from aer, 'air'. Both these, of course, are perfectly fitting for her. And if we consider her name jointly with that of Zeus we get a perfect combination for the two rulers of the heavens, with Zeus perhaps ruling the upper air (aither) and Hera the lower, denser air (aer) (see Aërope). Other proposed derivations have been erao, 'to love' (again, fitting for the goddess of marriage, as she was), and even era, 'earth' (the Latin terra), although this seems less justifiable.
Perhaps the true meaning of her name is nearer 'protectress', since this seems to be the basic sense of the root of her name and that of 'hero', as Greek hews is linguistically related to Latin servare, 'to safeguard' (compare English 'servant'), with the original name being something like Herwa.