What Does Os Mean In Size

What does the size of the operating system mean? 3

Hi, I looked on eBay and said that OS size is one of them. what is the meaning of this?

update

thank you all !

I think one size

One size fits all

This means size :)

She read Agatha Christie's Come, Tell Me Where Do You Live (her memoirs of her trip with her archaeologist husband) and was amazed at what was considered OS and then explained what HUGE meant. Which means extraordinary (big!)

One size (as in one size)

What Does Os Mean In Size

One size, one size.
These items include hats, scarves, caps, gloves, socks (sometimes), sunglasses, bracelets, etc.
One size fits most)
The size of this particular item