B1
something that you say or do in order to show that you are grateful for something
Dictionary examples:
His 'thank you' was a pizza with 'THANKS' spelled in pepperoni! (0.0)
His 'thank you' was so loud, it woke up the neighbors! (0.0)
His 'thank you' was a song that lasted for three hours! (0.0)
The chocolates were a thank you for looking after the children. (15.8)
I'd like to say a big thank you to everyone for all their help. (21.0)