tough·ie 
/ˈtʌfi/ noun
plural tough·ies /ˈtʌfi/ noun [count] informal 1 : a difficult problem or question
▪ The last question on the test was a toughie. 2 : a tough person : a strong person who is not afraid
▪ He thinks he's a real toughie.
▪ The last question on the test was a toughie.
▪ He thinks he's a real toughie.
