Source : Webster's Revised Unabridged Dictionary (1913)

Menace \Men"ace\, v. t. [imp. & p. p. {Menaced} ([=a]st); p. pr.
   & vb. n. {Menacing}.] [OF. menacier, F. menacer. See
   {Menace}, n.]
   1. To express or show an intention to inflict, or to hold out
      a prospect of inflicting, evil or injury upon; to
      threaten; -- usually followed by with before the harm
      threatened; as, to menace a country with war.

            My master . . . did menace me with death. --Shak.

   2. To threaten, as an evil to be inflicted.

            By oath he menaced Revenge upon the cardinal.
                                                  --Shak.

Source : WordNet®

menacing
     adj : threatening or foreshadowing evil or tragic developments; "a
           baleful look"; "forbidding thunderclouds"; "his tone
           became menacing"; "ominous rumblings of discontent";
           "sinister storm clouds"; "a sinister smile"; "his
           threatening behavior"; "ugly black clouds"; "the
           situation became ugly" [syn: {baleful}, {forbidding}, {minacious},
            {minatory}, {ominous}, {sinister}, {threatening}, {ugly}]