Other contributors have said "Suffix that means out?" is the same question as "What does the suffix dom mean?" If you believe that these are not asking the same thing and should be answered differently, click here
It means belonging to a suffix, such as 'a suffix's spelling'. A suffix is an ending you attach to a word to change its meaning: an example would be combining the word 'attend' with the suffix...
A suffix is something that comes after a word. Prefix is before. "An affix added to the end of a word or stem, serving to form a new word or functioning as an inflectional ending, such as -ness in...