the property resulting from being one of a series of graduated measurements (as of clothing)
"he wears a size 13 shoe"
the actual state of affairs
"that's the size of the situation"
"she hates me, that's about the size of it"
a large magnitude
"he blanched when he saw the size of the bill"
"the only city of any size in that area"
An assize.
"The artist mixed a few drops of size into his water before applying it to the raw canvas to prevent the oil paint from soaking through."
A thin, weak glue used as primer for paper or canvas intended to be painted upon.
In plain English: Size is how big or small something is compared to other things.
"The size of the box was much smaller than I expected."
cover or stiffen or glaze a porous material with size or sizing (a glutinous substance)
"The potter carefully sized the unglazed clay pots to seal their pores before firing them in the kiln."
sort according to size
"The librarian asked us to line up all the books by height so she could find them easily."
make to a size; bring to a suitable size
"The tailor will cut and sew the fabric until it is sized perfectly for your frame."
To adjust the size of; to make a certain size.
"Before painting the new cabinets, we need to size all the panels to ensure the finish adheres properly."
To apply glue or other primer to a surface which is to be painted.
In plain English: To size something means to figure out how big it is.
"We need to size up the furniture before we buy it to make sure it fits in the room."
Usage: Use this verb when physically altering an object's dimensions, such as resizing a photo or adjusting clothing measurements. It is distinct from simply describing how large something already is, which requires using "size" as a noun or adjective.
The word "size" entered English in the 14th century from Old French, originally referring to a law or regulation that determined payment amounts. It eventually replaced the native Old English term for bigness to describe physical dimensions.