Word part · Greek root
Astr root words: meaning and 16 examples
In short
The Greek root astr (from Greek) means "star". It is also spelled aster and astro. Words with it include disaster, disasters, disastrous, disastrously, astrology and astrologer. Spelled astro at the front of many words (astronomy) and aster inside others (disaster, asterisk).
- Part
- astr
- Meaning
- star
- Origin
- Greek
- Also spelled
- aster, astro
- Words listed
- 16
Spelled astro at the front of many words (astronomy) and aster inside others (disaster, asterisk). An asterisk is a little star you write.
Words with the Greek root astr
The list runs from shorter, common words to longer ones. The bands are a rough guide built from syllable count and how common each word is in our word list, not a grade-level standard. Read each word, then its word sum.
Colors:prefixroot or basesuffix
Next: longer words (about grades 5 and 6)
| Word | Word sum | What it means |
|---|---|---|
| disaster | dis (prefix)+aster (root or base)→disaster | a terrible event, once blamed on a bad star |
| disasters | dis (prefix)+aster (root or base)+s (suffix)→disasters | more than one disaster |
| disastrous | dis (prefix)+astr (root or base)+ous (suffix)→disastrous | causing great harm, or going very badly |
| astral | astr (root or base)+al (suffix)→astral | having to do with the stars |
More words: asteroid, asteroids, asterisk, asterisks
Stretch: long or less common words (about grades 7 and 8)
| Word | Word sum | What it means |
|---|---|---|
| disastrously | dis (prefix)+astr (root or base)+ous (suffix)+ly (suffix)→disastrously | in a way that goes very badly |
| astrology | astro (root or base)+logy (root or base)→astrology | the old belief that stars and planets shape people's lives |
| astrologer | astro (root or base)+log (root or base)+er (suffix)→astrologer | a person who practices astrology |
| astrophysics | astro (root or base)+physics (root or base)→astrophysics | the science of how stars and planets work |
More words: astronomy, astronomer, astronomers, astronomical
Where does astr sit in a word?
A root can come first, last or in the middle. Students who only look at the start of a word miss half of these.
- At the start:
- astrology, astrologer, astrophysics, astral
- In the middle:
- disastrous, disastrously
- At the end:
- disaster, disasters
How do you teach the root astr?
Start with astronomy, a word most students know from space units: the study of stars and planets. Then show asterisk, the little star mark they type on a keyboard, and let them find the aster inside it. The surprise word is disaster. Long ago people believed the stars could bring bad luck, so a disaster was a bad star. Students remember the root because of that story, and it makes a good hook.
A quick routine
Draw a star and write astr, aster and astro under it. Say, "All three spellings mean star. Find the star in each word." Read astronomy, asteroid, asterisk and disaster. The student points to the root and tells you the link, such as "an asterisk looks like a star." Then dictate disastrous and ask, "Where did the e from aster go?" The student says the spelling is astr before ous.
What do students mix up with astr?
The letters a-s-t-e-r turn up in many words with no star in them: master, faster, plaster, toaster. In these, the er is a suffix or part of a base word. A good check is to ask, "Could this have anything to do with stars or space?" If not, it isn't this root. Astronomy and astrology are easy to mix up as well. Astronomy is the science, and astrology is a belief.
For the sounds inside these words, see the phonics word lists. Routines that fit: meanings of prefixes and suffixes, circle the parts, read the base and flexible routine for big words.
Questions people ask
What does the root astr mean?
Astr means "star". It is a Greek root, also spelled aster and astro. Spelled astro at the front of many words (astronomy) and aster inside others (disaster, asterisk). An asterisk is a little star you write.
What are some words with the root astr?
Start with disaster, disasters, disastrous and astral. Then move to disastrously and astrology. This page lists 16 words in all, most with a word sum that shows the parts.
Why is an asteroid called that?
Aster means star and oid means like, so an asteroid is a star-like thing. Through early telescopes, asteroids looked like small points of light, much like faint stars.
Related word parts
- dis-not, the opposite of, or apart
- logythe study of
- geoearth
- -ousfull of, or having
- -alhaving to do with
Terms on this page: morpheme, root, prefix, suffix, base word, word sum, morphology.
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