astr

IPA/ˈastə/
IPA/ˈæstɚ/

astr — combining form

1. a word part meaning 'star' or 'outer space,' used at the start of scientific wor

1.構詞成分B2
釋義

a word part meaning 'star' or 'outer space,' used at the start of scientific words like astronomy (the study of stars) and astronaut (someone who travels into space)

例句

Priya checked the astronomy app on her phone to find Venus and Jupiter.

word formation: astr- + -onomy = astronomy (study of stars)

The astronaut on the space station sent a video message to schoolchildren in Lagos.

文法句型

astr- + suffix

astro- + suffix

用法筆記

This is the most common sense of 'astr-'. It appears in scientific words about stars and the universe. The form 'astro-' (with an 'o') is used before most consonants, while 'astr-' appears before vowels.

常見錯誤

The astronomer walked on the moon in 1969.
The astronaut walked on the moon in 1969.
💡an astronomer studies space from Earth using telescopes; an astronaut travels into space.

2. a word part used in words connected with astrology — the belief system that clai

2.構詞成分B2
釋義

a word part used in words connected with astrology — the belief system that claims the positions of stars and planets can tell us about human lives and the future

例句

The astrologer told Diego that the coming year would bring him three new friendships.

word formation: astr- + -ologer = astrologer

Fatima read her astrological birth chart out of curiosity, not deep belief.

文法句型

astr- + -ology

astr- + -ologer

astr- + -ological

用法筆記

Distinguish from sense 1 (STAR AND SPACE): words in this sense relate to astrology (a belief system), not astronomy (a science). 'Astrology' and 'astronomy' share the same root but refer to different fields.

常見錯誤

I study astrology at university to learn about black holes.
I study astronomy at university to learn about black holes.
💡astronomy is the science of stars and space; astrology is the belief that star positions affect human lives.

3. a word part used in cell biology for structures that have a star-like shape, suc

3.構詞成分C1
釋義

a word part used in cell biology for structures that have a star-like shape, such as certain cells and the fibres that form during cell division

例句

Under the microscope, astrocytes formed a delicate network around the brain cells.

word formation: astr- + -cyte = astrocyte (star-shaped cell)

The lab diagram showed astral fibres pulling chromosomes apart during cell division.

文法句型

astr- + -ocyte

astr- + -al

astr- + -osphere

用法筆記

This sense is specialised and appears mainly in biology and medical texts. It is rare outside academic contexts. The star-like shape is visible only under a microscope.