To recite a prayer of invocation or thanksgiving at meal time.(verb)
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Use "say grace" in a sentence
"As the recipient of graces experiences, on his part, sentiments of gratefulness, and expresses these sentiments in thanks, the word gratiae (plural of gratia) also stands for thanksgiving in the expressions gratias agere and Deo gratias, which have their counterpart in the English, to say grace after meals."
"Like families who say grace before meals in gratitude for the food on their plates, each evening the Farrells observed a strange way of expressing thanks."