Astronomy term for the sun's corona; also used for similar luminous rings around other celestial bodies.
See also: 光環
I got infected with COVID last week and took a week off work.
During the total solar eclipse, the sun's corona was clearly visible.
coronavirus
Abbreviation of コロナウイルス; commonly used in news and everyday speech to refer to the virus.
See also: コロナウイルス
コロナの感染が再び拡大している。
Coronavirus infections are spreading again.
Abbreviation of 新型コロナウイルス感染症; often used in contexts like コロナ禍 (the COVID-19 pandemic).
See also: 新型コロナウイルス感染症 · コロナ禍
コロナの影響で旅行をキャンセルした。
I canceled my trip because of COVID-19.
COVID cases are spreading in urban areas.
I wish the COVID situation would come under control soon.
Because of COVID, I ended up unable to go on the trip.
コロナ is an even more casual, conversational abbreviation for the disease, whereas 新型コロナウイルス感染症 is the precise official term used in medical and government contexts.
コレラ is the disease cholera, while コロナ refers to the coronavirus (or a solar corona), so despite the similar katakana sound they are unrelated diseases/concepts.
COVID-19 pandemic; coronavirus crisis
person obsessed with COVID-19; COVID-19 alarmist
COVID-19 recession
corona treatment; air plasma treatment
corona discharge
post-COVID-19 relaxation; easing of COVID-19 restrictions
pandemic fatigue; COVID-19 fatigue
novel coronavirus; COVID-19
coronagraph
From English 'corona', ultimately from Latin 'corona' meaning 'crown'. The virus-related senses are abbreviations of longer terms.
corona observatory