1) Coiner 1) Idiom inventor 2) Lexicographer 3) Lexicologist 
• (n.) One who introduces new words or new senses of old words into a language. • (n.) An innovator in any doctrine or system of belief, especially in theology; one who introduces or holds doctrines subversive of supernatural or revealed religion; a rationalist, so-called. • (n.) One who introduces new words or new senses of old word...
Ne·ol'o·gist noun [ Confer French néologiste .] 1. One who introduces new words or new senses of old words into a language. 2. An innovator in any doctrine or system of belief, especially in theology; one who introduces or holds doctrines subversive of supernatural or revealed ...
[n] - a lexicographer of new words and expressions
neologist 1. A lexicographer of new words and expressions or a person who coins or makes up new words. 2. Someone who invents or employs new words. 3. Anyone who introduces, or uses new words, or new senses of existing words. 4. A person who adopts new views, or new doctrines; especially, a new interpretation of sacred writings or views of theol...
noun a lexicographer of new words and expressions