Backwards, Back
The prefix of the word retroperitoneum is "retro-," which means behind, backwards, or on the other side.
Where the prefix retro- does not merely "reverse" the existing condition (which would already be the opposite e.g. retro-rocket), the opposite would be pro- (proactive, progressive, prograde, and prospective).
The prefix that means "backwards" is "retro-".
The prefix that fits the definition of backward or back is "re-".
take away the how and add an I to the beginning
The prefix of the word retroperitoneum is "retro-," which means behind, backwards, or on the other side.
Where the prefix retro- does not merely "reverse" the existing condition (which would already be the opposite e.g. retro-rocket), the opposite would be pro- (proactive, progressive, prograde, and prospective).
Periton- is the root and retro- the prefix for retroperitoneal.
Retro, or perhaps anti in some cases, such as anticlockwise.
The prefix that means "backwards" is "retro-".
Backwards, or back in time.
retrospect retrograde
retro
retro- eg: retrograde
Retro
The prefix that fits the definition of backward or back is "re-".
take away the how and add an I to the beginning