-ian +

(Latin: suffix form of -an from -ianus, a modifier of the main word to which it is attached: belonging to, coming from, being involved in, or being like something)

Appearing in such words as comedian, egalitarian, Bostonian, Italian, Smithsonian, mathematician, Alabamian, Californian, Arizonian, and Canadian. It is attached to the root of common or proper nouns with the meanings "of, pertaining to, from", or "like" the proper name appearing in the stem.

—Based on information from The Barnhart Dictionary of Etymology,
Edited by Robert K. Barnhart, The H.W. Wilson Company, 1988.
pyrotechnician
One skilled in pyrotechny; a maker of gunpowder, etc., or of fireworks.
ranarian
Frog-like; froggy.
saurian
1. Lizard; any of a former suborder of reptiles that included all lizards.
2. Relating to or resembling a lizard.
sectarian (adjective)
Relating to religious or political groups and the differences between them: "There are more and more reports about countries being split along sectarian lines and about sectarian violence."
septuagenarian
1. A person who is in his/her seventies.
2. Someone who is seventy to seventy-nine years old.
vegetarian (s) (noun), vegetarians (pl)
1. One who lives wholly or principally upon vegetable foods: A vegetarian is a person who on principle abstains from any form of animal food, or at least such as is obtained by the direct destruction of animal life.

Vegans strictly adhere to this regimen, but other vegetarians also consume eggs (ovovegetarians), or dairy products (lactovegetarians, or both (ovolactovegetarians).

2. Animals that live on vegetables.
3. Consisting of vegetables or plants.
vocabularian (s) (noun), vocabularians (pl)
Someone who gives much or a great deal of attention to words.