Words with the prefix semi-
semi- means “half; partially”, from Latin.
14 examples of the prefix semi-
- semifinalsemi- + finalround before the final
- semicirclesemi- + circlehalf of a circle
- semiformalsemi- + formalpartially but not fully formal
- semiskilledsemi- + skilledpartially but not fully skilled
- semisweetsemi- + sweetonly partially sweet
- semiconductorsemi- + conductorpartially conducts electricity
- semiannualsemi- + annualoccurring twice a year
- semidetachedsemi- + detachedhalf-separated from adjoining house
- semiautomaticsemi- + automaticonly partly automatic in operation
- semiprecioussemi- + preciousof lesser value than precious
- semipermeablesemi- + permeableallowing only partial passage through
- semioticsemi- + otic (sign)of signs and their meanings
- semiaridsemi- + aridpartially dry, limited rainfall
- semitransparentsemi- + transparentonly partially allowing light through
- semioticsemi- + oticrelating to signs and meaning
How semi- works
The prefix 'semi-' attaches to nouns, adjectives, and occasionally verbs without changing the base word's part of speech, and it never assimilates or changes its spelling regardless of the first letter of the base word. It consistently means 'half' or 'partially,' often softening or halving the quality expressed by the root.
Watch out: The word 'seminal' looks like it contains 'semi-' meaning half, but it actually derives from Latin 'semen' (seed) and means foundational or influential, with no connection to the prefix.
To see prefixes combine with other parts, try the word dissector and root builder, or test yourself in the vocabulary quiz.
Other common prefixes
Questions people ask
What does the prefix semi- mean?
semi- means “half; partially”. It comes from Latin. The prefix 'semi-' attaches to nouns, adjectives, and occasionally verbs without changing the base word's part of speech, and it never assimilates or changes its spelling regardless of the first letter of the base word. It consistently means 'half' or 'partially,' often softening or halving the quality expressed by the root.
What are some examples of words with the prefix semi-?
semifinal, semicircle, semiformal, semiskilled, semisweet, semiconductor, semiannual, semidetached. The full list of 14 examples, with what each one literally means, is above.
Which words look like they have the prefix semi- but don’t?
The word 'seminal' looks like it contains 'semi-' meaning half, but it actually derives from Latin 'semen' (seed) and means foundational or influential, with no connection to the prefix.
What is a prefix?
A prefix is a word part added to the front of a base word or root to change its meaning, like un- in unhappy or re- in rewrite. It does not usually change the part of speech.