Resembling or characteristic of a reptile.(adjective)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "reptilian" in a sentence
"It's part of what we call the reptilian core of the brain, associated with wanting, with motivation, with focus and with craving."
"The oldest, which he calls the reptilian brain, controls aggression and passionate impulsiveness."
"One pays according to an iron schedule -- for every strength the balanced weakness; for every high a corresponding low; for every fictitious god-like moment an equivalent time in reptilian slime."