强迫的,推进的推进力
Impellent \Im*pel"lent\, a. [L. impellens, p. pr. of impellere.] Having the quality of impelling. Impellent \Im*pel"lent\, n. An impelling power or force. --Glanvill.
impellent adj : forcing forward or onward; impelling; "an impellent power"; "an impellent cause"