Final answer:
In the legend, the nymph that Juno condemned, with the curse of speaking only the last words heard and not being able to speak first, was Echo.
Step-by-step explanation:
In one legend, Juno condemned the nymph Echo, saying, "You shall still have the last word, but no power to speak first." This curse was a punishment for Echo's involvement in distracting Juno with long-winded conversations while Zeus, Juno's husband, engaged in affairs with other nymphs. As a result of the curse, Echo was left only able to repeat the last words spoken to her, effectively depriving her of her voice. This mythological story underlines themes of communication, deceit, and divine retribution within the context of ancient lore.