Reptilian means like a reptile, or cold and unfeeling. Reptilian skin, a reptilian stare, reptilian calm.
The figurative sense borrows the stillness and the unblinking eye, and it is always an insult. The reptilian brain is a popular idea from an old model of brain evolution that has not survived scrutiny, though the phrase persists. Note that the Latin reptilis means crawling, from repere, to creep.
1adjectivereptileLike a reptile.
“The creature had cold, reptilian eyes and a long forked tongue.”
2adjectivereptilianCold and unfeeling.
“The banker gave a thin, reptilian smile as he refused the loan.”
reptilian is a quality of coldness.
Reptile plus -ian, from Latin reptilis, crawling, from repere, to creep. Reptiles are literally creepers.
Latin
rēptile
Old French
reptile
Middle English
reptil
English
reptile
English, today
reptilian
Built from
From reptile + -ian, replacing earlier reptilious and adjectival reptile. reptile comes from Middle English reptil, from Old French reptile, from Latin rēptile, neuter of reptilis (“creeping”), from Latin rēpō (“to creep”), from Proto-Indo-European rep- (“to creep, slink”) (Pokorny; Watkins, 1969).
Etymology from Wiktionary, CC BY-SA