# planetary

/ˈpɫænəˌtɛɹi/ (US) · /plˈænɪtəɹi/ (UK)

Source: https://englishreference.com/word/planetary
Updated: 2026-06-20

## Senses

### 1. relating to planets

adjective · CEFR B2 · Technical

relating to planets or how they move around a star.

For teachers: relating to, or consisting of planets; specifically describing the orbital motion of celestial bodies within a solar system.

- Scientists are studying the planetary alignment that will happen next month.
- The probe was designed to withstand the extreme atmospheric pressures found during its descent into the planetary core of Jupiter.

Usage: Usually placed before the noun it modifies.

### 2. global or worldwide

adjective · CEFR B2 · Academic

relating to the whole Earth and everyone on it.

For teachers: relating to the entire planet Earth; often used in environmental or sociological contexts to denote a global scale.

- Climate change is a planetary problem that requires every country to work together.
- The report argues that we have already exceeded several planetary boundaries, risking irreversible damage to the Earth's ecosystem.

Usage: Commonly used in academic writing regarding the environment or sustainability.

### 3. a type of nebula

noun · CEFR C2 · Technical

a short way to say 'planetary nebula', which is a cloud of gas around a dying star.

For teachers: A clipped form of 'planetary nebula', referring to an astronomical object consisting of an expanding shell of ionized gas ejected from a red giant star.

- The astronomer pointed his telescope toward a bright planetary in the constellation.
- The high-resolution images revealed intricate structures within the planetary, suggesting a complex history of mass loss from the progenitor star.

Teaching tip: This noun use is highly specialized; most learners will only encounter the word as an adjective.

## Examples

- Scientists are studying planetary movements in our solar system.
- Climate change is a planetary challenge that requires every nation to work together.
- The probe's mission is to gather data on planetary formation by analyzing the chemical composition of the asteroid belt's largest bodies.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.