1. [adj]  of a leaf shape; narrowing to a slender point
2. [v]  make sharp or acute; taper; make (something) come to a point

ACUMINATE is a 9 letter word that starts with A.

1. \A*cu"mi*nate\, a. [L. acuminatus, p. p. of acuminare
   to sharpen, fr. acumen. See {Acumen}.]
   Tapering to a point; pointed; as, acuminate leaves, teeth,
   etc.
   

2. \A*cu"mi*nate\, v. t.
   To render sharp or keen. [R.] ``To acuminate even despair.''
   --Cowper.
   

3. \A*cu"mi*nate\, v. i.
   To end in, or come to, a sharp point. ``Acuminating in a cone
   of prelacy.'' --Milton.
   

1. Descibes a leaf that tapers abruptly to a sharp point.
2. Tapering gradually to a protracted point.
3. Drawn out into a long point; tapering point.