Neptune

noun

Nep·​tune ˈnep-ˌtün 

-ˌtyün

1

a

: the Roman god of the sea compare poseidon

b

: ocean

2

: the planet eighth in order from the sun see Planets Table

Neptunian

nep-ˈtü-nē-ən 

-ˈtyü-

adjective

Synonyms

• sea
• ocean

Examples of Neptune in a Sentence

sailors shipwrecked by the wild waves of Neptune

Recent Examples on the Web

With Neptune entering Aries on the 30th, your vision for the future is starting to expand. —Meghan Rose, Glamour, 1 July 2025

Mercury retrograde begins July 18th in Leo, joining Saturn and Neptune in the slowdown club. —Dossé-Via Trenou, Refinery29, 30 June 2025

Still, its trine to numinous Neptune inspires you to expand your horizons and share your visions and ideas with others. —Valerie Mesa, People.com, 28 June 2025

Enthusiasm for ideals is high today as Mercury aligns with Neptune. —Usa Today, USA Today, 28 June 2025

Word History

Etymology

Latin Neptunus

First Known Use

before the 12th century, in the meaning defined at sense 1a

Kids Definition

Neptune

noun

Nep·​tune ˈnep-ˌt(y)ün 

: the planet eighth in order from the sun see planet

Neptunian

nep-ˈt(y)ü-nē-ən 

adjective