A Quenya word hú glossed as either “hound” or “heart” (according to Christopher Gilson) appearing in rough notes on Words, Phrases and Passages from the Lord of the Rings from the late 1950s or early 1960s exploring the possible origins of S. huorn (PE17/86). This was followed by an unglossed variant form Q. hó, apparently derived from khōgo. Tolkien seems to have vacillated between primitive roots √KHUG/KHOG (the former being the basis for “dog” words in The Etymologies) or √KHON (the basis for “heart” words in The Etymologies), connections that were also pointed out by Christopher Gilson.
Neo-Quenya: Giving the tenuous nature of this word, I’d stick to better defined ᴹQ. huo “dog” from The Etymologies for purposes of Neo-Quenya.
hú noun "hound" (PE17:86), cf. huan, huo