The Collaborative International Dictionary of English v.0.48:

Impend \Im*pend"\, v. t. [L. impend[e^]re; pref. im- in +
   pend[e^]re to weigh out, pay.]
   To pay. [Obs.] --Fabyan.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Impend \Im*pend"\, v. i. [imp. & p. p. Impended; p. pr. & vb.
   n. Impending.] [L. impend[=e]re; pref. im- in + pend[=e]re
   to hang. See Pendant.]
   To hang over; to be suspended above; to threaten from near at
   hand; to menace; to be imminent. See Imminent.
   [1913 Webster]

         Destruction sure o'er all your heads impends. --Pope.
   Impendence

WordNet (r) 3.0 (2006):

impend
    v 1: be imminent or about to happen; "Changes are impending"

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "impend":
   approach, await, be as expected, be imminent, be in store, beetle,
   brew, come on, confront, draw near, draw nigh, draw on,
   expect it of, face, forthcome, gather, hang out, hang over, hover,
   impend over, jut, lie over, loom, lower, menace, near, overhang,
   project, project over, threaten, thrust over