English Reference

Word

mammalian

Phoneticsmam·malian

US/məˈmeɪɫiən/

UK/mæmˈeɪliən/

Definition

adj. relating to mammals, which are animals that feed their babies with milk from the mother's body.

adj. relating to or characteristic of the class Mammalia. Typically describes biological processes, physical traits, or species belonging to this group.

Examples

“Whales are mammalian creatures that live in the ocean.”

“The researchers studied mammalian brain development to better understand how human memory functions.”

“The transition from reptilian to mammalian jaw structures represents one of the most well-documented transformations in the vertebrate fossil record, illustrating a shift in both feeding and hearing mechanisms.”

Examples

simple

“Whales are mammalian creatures that live in the ocean.”

contextual

“The researchers studied mammalian brain development to better understand how human memory functions.”

complex

“The transition from reptilian to mammalian jaw structures represents one of the most well-documented transformations in the vertebrate fossil record, illustrating a shift in both feeding and hearing mechanisms.”

Usage

Primarily used as an adjective in scientific and academic contexts; less common as a noun referring to a specific mammal.

Real-World Examples

Common in science writing

“It could be evidence of the general switch from laying eggs to giving birth to live young early on in the mammalian lineage.”
ScienceDaily · 13 Aug 2026
“Similar signals are involved in mammalian caregiving, suggesting that evolution may have followed the same basic blueprint across very different animals.”
ScienceDaily · 1 Aug 2026

Etymology

From mammal + -ian.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Domain

Zoology

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

Scan code

englishreference.com/q/mammalian

English Reference