Hate
Hiroshima and Holocaust are history words. They begin with the letter h.
Hubble telescope and hydrogen are space words. They begin with the letter h.
happenHalloweenhardenhandymanhandgunhalonharpoonhooliganhastenhairpinheronheartburnheathenheightenhadronhenhexagonheptagonheparinheavenheadpinhiddenhighbornhoganhatpinhadronhellionhornhorsemanhomonymhousemanhumanhumanitarianhyphen
some 5 letter words that starts with "h" are heart and horse
Hydrangea and Hibiscus are nature words. They are flowers species.