-ist

(Greek > Latin: a suffix; one who believes in; one who is engaged in; someone who does something)

hydroponicist, hydroponist (s) (noun), hydroponicists; hydroponists (pl)

Someone who is a specialist in hydroponics, that means growing plants without soil, in beds of sand, gravel, or similar supporting material flooded with nutrient solutions: Mr Green was a hydroponicist who was a specialist in the cultivation of plants in a nutritious water mixture instead of in soil.

hydrotherapist

A specialist in or practitioner of hydrotherapy.

hyetologist

hygeist

Someone who is a specialist in hygiene; a sanitarian.

hygienist

1. One who is skilled in the science of health and its maintenance. Synonym: hygieist.
2. Someone who specializes in hygiene, or in a specific branch of hygiene, such as, a dental hygienist.

hylologist

hylopathist

hylotheist (s) (noun), hylotheists (pl)

A person who believes that God and the material world are the same.

hylozoist

hypernephelist

Someone who goes above and beyond the clouds.

hypertrichologist

A person who treats unsightly facial hair.

hypnologist

A specialist in the phenomena of sleep and/or hypnosis.

hypnotist