1. [n]  (architecture) a slender upright spire at the top of a buttress of tower
2. [n]  a lofty peak
3. [n]  the highest level or degree attainable; "his landscapes were deemed the acme of beauty"; "the artist's gifts are at their acme"; "at the height of her career"; "the peak of perfection"; "summer was at its peak"; "...catapulted Einstein to the pinnacle of fame"; "the summit of his ambition"; "so many highest superlatives achieved by man"; "at the top of his profession"
4. [v]  raise on or as if on a pinnacle; "He did not want to be pinnacled"
5. [v]  set on or as if on a pinnacle; "pinnacle a pediment"

1. \Pin"na*cle\, n. [OE. pinacle, F. pinacle, L.
   pinnaculum, fr. pinna pinnacle, feather. See {Pin} a peg.]
   1. (Arch.) An architectural member, upright, and generally
      ending in a small spire, -- used to finish a buttress, to
      constitute a part in a proportion, as where pinnacles
      flank a gable or spire, and the like. Pinnacles may be
      considered primarily as added weight, where it is
      necessary to resist the thrust of an arch, etc.
   
            Some renowned metropolis With glistering spires and
            pinnacles around.                     --Milton.
   
   2. Anything resembling a pinnacle; a lofty peak; a pointed
      summit.
   
            Three silent pinnacles of aged snow.  --Tennyson.
   
            The slippery tops of human state, The gilded
            pinnacles of fate.                    --Cowley.
   
   

2. \Pin"na*cle\, v. t. [imp. & p. p. {Pinnacled}; p. pr. &
   vb. n. {Pinnacling}.]
   To build or furnish with a pinnacle or pinnacles. --T.
   Warton.
   
   

a little wing, (Matt. 4:5; Luke 4:9). On the southern side of the temple court was a range of porches or cloisters forming three arcades. At the south-eastern corner the roof of this cloister was some 300 feet above the Kidron valley. The pinnacle, some parapet or wing-like projection, was above this roof, and hence at a great height, probably 350 feet or more above the valley.