Use de exclude character [^]
[^<]h\w+
But i think this way may work better for what you want, since it generates a match for every word beginning with h that's not a
(?!<)h\w+
Even better, do the following match:
((?!<)h\w+)
(close attention, there is a blank space just before the first (
)
If the text is:
html teste homem carro agharro hzete h
It will do a full match with " homem" and " hzete", being the first match groups the word you want. "homem","hzete".
I would recomend you a graphical regex validation tool, so you see live the expressions you are writing.
A good one is https://regex101.com/
Hope this helps.