Word part · Latin prefix
Prefix semi- words: meaning and 12 examples
In short
The Latin prefix semi- (from Latin) means "half, or partly". Words with it include semicircle, semicircles, semifinal, semifinals, semicolon and semiannual. Semi- can mean exactly half (a semicircle) or only partly (semisweet chocolate).
- Part
- semi-
- Meaning
- half, or partly
- Origin
- Latin
- Words listed
- 12
Semi- can mean exactly half (a semicircle) or only partly (semisweet chocolate). Ask which one fits.
Words with the Latin prefix semi-
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 |
|---|---|---|
| semicircle | semi (prefix)+circle (root or base)→semicircle | half of a circle |
| semiannual | semi (prefix)+annual (root or base)→semiannual | happening every half year |
| semisweet | semi (prefix)+sweet (root or base)→semisweet | only partly sweet |
| semiarid | semi (prefix)+arid (root or base)→semiarid | partly dry, with a little rain |
Stretch: long or less common words (about grades 7 and 8)
| Word | Word sum | What it means |
|---|---|---|
| semicircles | semi (prefix)+circle (root or base)+s (suffix)→semicircles | more than one semicircle |
| semifinal | semi (prefix)+final (root or base)→semifinal | the game just before the final |
| semifinals | semi (prefix)+final (root or base)+s (suffix)→semifinals | the games just before the final |
| semicolon | semi (prefix)+colon (root or base)→semicolon | a mark that is part comma, part colon |
| semiprecious | semi (prefix)+precious (root or base)→semiprecious | valued, but less than a precious gem |
| semiformal | semi (prefix)+formal (root or base)→semiformal | partly dressed up |
| semidarkness | semi (prefix)+dark (root or base)+ness (suffix)→semidarkness | a dim light that is partly dark |
| semiconductor | semi (prefix)+con (prefix)+duct (root or base)+or (suffix)→semiconductor | a material that lets electricity pass only partly |
How do you teach the prefix semi-?
Semi- means half or partly. Start with semicircle, because you can draw it: a circle cut in half. Then semifinal, the game before the final, which is the halfway step in a tournament. Last, show semisweet and semiformal, where the meaning shifts to partly. Talking about that shift is worth a minute; it trains students to test a meaning instead of guessing.
A quick routine
Draw a full circle, then half of one. Say, "Semi means half. This is a semicircle." Show semisweet and ask, "Is semisweet chocolate exactly half sweet?" The student should say, "No, partly sweet." Then write three more and have the student label each half or partly: semifinal, semicolon, semiarid. Talk through any that could go either way.
What do students mix up with semi-?
Semi- and hemi- both mean half, and so does demi in a few words. Students mostly meet semi, so teach that and mention hemisphere only when it comes up in geography. Seminar and semester look like semi words but aren't: seminar comes from a word for seed. Remove semi and see if a base word is left.
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 prefix semi- mean?
Semi- means "half, or partly". It is a Latin prefix. Semi- can mean exactly half (a semicircle) or only partly (semisweet chocolate). Ask which one fits.
What are some words with the prefix semi-?
Start with semicircle, semiannual, semisweet and semiarid. Then move to semicircles and semifinal. This page lists 12 words in all, most with a word sum that shows the parts.
Why is a semicolon called that?
It is half colon, half comma: the top is a dot like a colon and the bottom is a comma. Semi means half or partly, so the name describes the mark.
Related word parts
- multi-many
- bi-two, or every two
- mid-middle
- uni-one
- con-with, or together
- duclead, or bring
- -nessthe state of being
- -ora person or thing that does something
Terms on this page: morpheme, root, prefix, suffix, base word, word sum, morphology.
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