Source : Webster's Revised Unabridged Dictionary (1913)

Inflential \In`flen"tial\, a. [See {Influence}.]
   Exerting or possessing influence or power; potent;
   efficacious; effective; strong; having authority or
   ascendency; as, an influential man, station, argument, etc.

         A very influential Gascon prefix.        --Earle.