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 of Neptune

• sea
• ocean

Examples of Neptune in a Sentence

sailors shipwrecked by the wild waves of Neptune

Recent Examples on the Web

Players jump between planets and moons with real-life equivalents such as Mars, Deimos, Neptune, Mercury, and Earth. — Luke Kemp, Space.com, 18 June 2026

Venus aligns with Neptune and struggles with Pluto today, creating a mixed bag in relationships. — Usa Today, USA Today, 17 June 2026

Loving Venus moves through your 11th House of Friends and trines imaginative Neptune in your 7th House of Partnership, so collaboration feels graceful and heartfelt. — Tarot.com, Sun Sentinel, 16 June 2026

As the moon joins forces with Neptune, inspiration returns in flashes, but its sextile to Uranus supports fresh ideas, emotional breakthroughs and the courage to try something new. — Valerie Mesa, PEOPLE, 9 June 2026

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