hippopotimus
Help by The Beatles.
Hyacinth is a spring flower. It begins with H.
holly
hucksterism
Hecate
Holly and holiday are Christmas words. Hark The Herald Angels Sing is a Christmas carol.
The Christmas song with the initials H A T I is probably "The Holly and the Ivy". The song is a traditional British Christmas carol. Cecil Sharp is credited with collecting the music and most of the words and being the first to publish them.
Horseradish is a vegetable. It begins with the letter h.
* heaven * hasten
whitefish, washcloth
Holy Night