thank–you 
/ˈθæŋkˌju:/ noun
plural thank–yous /ˈθæŋkˌju:/ noun [count] : something that you give or do to show thanks : a polite expression of thanks — usually singular ▪ They threw him a big party as a thank-you for his work at the community center. ▪ Have you sent out the thank-yous [=notes/cards/letters thanking people for their gifts, help, etc.] yet? — often used before another noun ▪ a thank-you note/letter/gift
