How to spell infectious

hear itin·fec·tious/ɪn'fɛkʃəs/adjectiveSchwa and roots

What it means: Easily spread to others.

In a sentence: The doctor's laugh was so infectious that everyone started giggling.

The part people get wrong

Watch for an unstressed vowel that is hard to hear. Often misspelled as infectous or infectius.

Same family: infection, infected, infective, infectiousness, infectious disease. If you can spell one, the shared part carries to the others.

Where it comes from: “Infectious” comes from the Latin verb *infectus*, past participle of *inficere*, meaning “to stain, taint, or corrupt.” Over time, English shifted the idea from “tainting” to the modern sense of spreading disease—or even spreading emotions like laughter.

Patterns it uses: The unstressed vowel (schwa)

Try spelling it

You will hear the word and a sentence. Type it and press Enter. Then four more words from the same level, so you know where you stand.

Words like this

infection · victorious · hilarious · notorious · rebellious · luxurious · beneficiary · verification

Spelling.School is a spaced-repetition spelling practice: ten minutes a day, every word spoken aloud, every miss explained, and every word coming back just before you would forget it. Try five words without signing up.