R0

From English reproduction (“R”) + zero (“0”).

R₀

1. (epidemiology) The basic reproduction ratio

• Basic reproduction number on Wikipedia.Wikipedia

As "R-nought":

• (General American) IPA^(key): /ɑɹˈnɔt/
• (Received Pronunciation) IPA^(key): /ɑːˈnɔːt/
• (cot–caught merger) IPA^(key): /ɑɹˈnɑt/

As "R-zero":

• (General American) IPA^(key): /ɑɹˈzɪɹoʊ/
• (Received Pronunciation) IPA^(key): /ɑːˈzɪəɹəʊ/

R₀ (plural R₀s)

1. R₀ (“basic reproductive rate”)

• nought
• R

• -0r