The etymology of atonement comes from the Latin adunare.  Ad, meaning, “to or at,” and unum, meaning, “one,” or in other words, the roots of the word atone mean, “united.”  With adunare is -ment, from the Latin mentum which was added to verbs to represent the product of the action of that verb.

Thus, the literal translation of the word atonement is, “the result of unity.”

Does that make it easier for you?