We don't have synonyms for impetent yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are implement, impatient and impotent.
°Lacking in power, as to act effectively; helpless: "Technology without morality is barbarous; morality without technology is impotent" (Freeman J. Dyson).
°Lacking in power, as to act effectively; helpless: "Technology without morality is barbarous; morality without technology is impotent" (Freeman J. Dyson).