The abbreviation for "Super Sized Big Beautiful Woman."
Dimensions Magazine defines SSBBW as a woman who is over 350 pounds. This wiki uses the same definition, but adds a separate category for the Ultra-SSBBW.
Ladies in this category generally weigh between 350 and 600 pounds. They are larger than BBW and smaller than USSBBW.
See SSBBW for a list of models in this category.