1sub 
/ˈsʌb/ noun
plural subs /ˈsʌb/ noun [count] informal 1 : someone who does the job of another person when that person is not able to do it : substitute
▪ The team's subs need to be versatile. ▪ (US) We had a sub [=substitute teacher] in English class all week. 2 Brit : subeditor
▪ The team's subs need to be versatile. ▪ (US) We had a sub [=substitute teacher] in English class all week.
— compare 3sub
