impellent

impellent
    adj 1: forcing forward or onward; impelling; "an impellent
           power"; "an impellent cause"
    

Impellent \Im*pel"lent\, a. [L. impellens, p. pr. of impellere.]
   Having the quality of impelling.
   [1913 Webster]
    

Impellent \Im*pel"lent\, n.
   An impelling power or force. --Glanvill.
   [1913 Webster]