The correct spelling of the word "retro ceding" is with a space between 'retro' and 'ceding', as they are two separate words. 'Retro' is pronounced as /ˈrɛtroʊ/ and means relating to or reviving the styles and fashions of the past. 'Ceding' is pronounced as /ˈsiːdɪŋ/ and means to give up or surrender something. Therefore, 'retro ceding' refers to the act of relinquishing something from the past or reviving a style from a bygone era. Make sure you spell the word correctly if you want to use it in your writing.
The term "retro ceding" does not have a specific etymology because it is not a commonly used word or a recognized English word. It seems to be a combination of the prefix "retro-" meaning "backward" or "backwards" and "ceding" which is a form of the verb "cede" meaning "to give up" or "to yield". As such, "retro ceding" might imply the act of giving up or yielding something in a backward or reverse manner. However, it is important to note that "retro ceding" is not a widely accepted or standard term in English usage.