ウイルス

also: ウィルス

ウ

イ

ル

ス

Common wordJLPTN3Freq.FrequencyTop 5,000

Meanings

1

noun

General noun for a virus, used in medical, biological, and computer-security contexts.

from Latin

ウイルスUsage76%
Standard katakana spelling and the highest-priority form.
ウィルスUsage24%
Common variant spelling with small ィ; widely understood, though ウイルス is the standard form in many contexts.

細さい菌きん
Means a bacterium; unlike ウイルス, it refers to a cellular microorganism and is often contrasted with viruses in medical contexts.
ワクチン
Means a vaccine; it is something used to prevent infection or serious illness, not the virus itself.

Katakana loanword for 'virus'; it is from Latin, but the exact route into Japanese is not specified here.