What does are mean?
The definition of are
Are.
Etym: [AS. (Northumbrian) aron, akin to the 1st pers. pl. forms, Icel. erum, Goth. sijum, L. sumus, Gr. smas; all from a root as. Am and Is, and cf. Be.]

The present indicative plural of the substantive verb to be; but etymologically a different word from be, or was. Am, art, are, and is, all come from the root as.

Are, n.
Etym: [F., fr. L. area. See Area.] (Metric system)

The unit of superficial measure, being a square of which each side is ten meters in length; 100 square meters, or about 119.6 square yards.