Final answer:
The prefix 'retro-' in the word retrospect means 'backwards' or 'in past time,' and it changes the base word 'spect' to mean 'look back' or 'review' of past events.
Step-by-step explanation:
The prefix in the word retrospect is 'retro-'. This prefix originates from Latin and means 'backwards' or 'in past time.' When added to the base word 'spect,' which comes from the Latin 'specere,' meaning 'to look,' the prefix alters the meaning of the word to 'look back' or 'review.' In retrospect, it's generally understood as a consideration or review of past events or situations.