The Collaborative International Dictionary of English v.0.48:

Potent \Po"tent\, a. [L. potens, -entis, p. pr. of posse to be
   able, to have power, fr. potis able, capable (akin to Skr.
   pati master, lord) + esse to be. See Host a landlord, Am,
   and cf. Despot, Podesta, Possible, Power,
   Puissant.]
   1. Producing great physical effects; forcible; powerful'
      efficacious; as, a potent medicine. "Harsh and potent
      injuries." --Shak.
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            Moses once more his potent rod extends. --Milton.
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   2. Having great authority, control, or dominion; puissant;
      mighty; influential; as, a potent prince. "A potent
      dukedom." --Shak.
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            Most potent, grave, and reverend signiors. --Shak.
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   3. Powerful, in an intellectual or moral sense; having great
      influence; as, potent interest; a potent argument.
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   Cross potent. (Her.) See Illust. (7) of Cross.
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   Syn: Powerful; mighty; puissant; strong; able; efficient;
        forcible; efficacious; cogent; influential.
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