Genesis11:1

Now all the earth was of one lip

and [the] words [of it were] one.

At that time all humans in the world spoke the same language; they could understand each other’s words.

This word means “edge, bank, shore, brim, brink, border, lip.” By extension of lip, it was also used of “speech or language.”

This is a plural form of the word “one.” How could they have a plural for “one”? Among its uses was the idea of “similar.”