Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Neo- \Ne"o-\ [Gr. ne`os youthful, new. See New.] A prefix meaning new, recent, late; and in chemistry designating specifically that variety of metameric hydrocarbons which, when the name was applied, had been recently classified, and in which at least one carbon atom is connected directly with four other carbon atoms; -- contrasted with normal and iso-; as, neopentane; the neoparaffins. Also used adjectively.
Douglas Harper's Etymology Dictionary
word-forming element meaning "new, recent," used in a seemingly endless number of adjectives and nouns, mostly coined since c.1880, from Greek neo-, comb. form of neos "new, young, youthful; fresh, strange; lately, just now," from PIE root *newo- (see new).
Wiktionary
pre. 1 new. 2 contemporary. 3 (context organic chemistry English) Having a structure, similar to that of neopentane, in which each hydrogen atom of a methyl group has been replaced by an alkyl group.
Usage examples of "neo-".
The murders reminded him that neo- Nazis were as cold as the monsters who inspired them, from Hitler to Heydrich to Mengele.
If the neo- Nazis managed to get out of the building, the other six agents in the support group would be in position, in the street, to pick them up.
The last thing the governments of Germany and America wanted was an incident involving the military that might galvanize the neo- Nazis.
If he broke the law or even if he were found out, the neo- Nazis would spin it as if they were being persecuted, ganged up on.
He only hoped that Jody didn't take him for a neo- Nazi and drop from a tree.