We don't have synonyms for square meters yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are square meter and square metre.
(n) :
US spelling of square metre. [A standard unit of area, regardless of its shape, equal to the area of a square whose sides are one metre long (that is, an area one meter square) Symbol: m²]
(n) :
US spelling of square metre. [A standard unit of area, regardless of its shape, equal to the area of a square whose sides are one metre long (that is, an area one meter square) Symbol: m²]