1. [n]  someone from whom you are descended (but usually more remote that a grandparent)
2. [n]  position or state of being dominant or in control; "that idea was in the ascendant"
3. [adj]  most powerful or important or influential; "the economically ascendant class"; "D-day is considered the dominating event of the war in Europe"
4. [adj]  tending or directed upward; "rooted and ascendant strength like that of foliage"- John Ruskin

ASCENDANT is a 9 letter word that starts with A.

1. \As*cend"ant\, n. [F. ascendant, L. ascendens; p. pr.
   of ascendere.]
   1. Ascent; height; elevation. [R.]
            Sciences that were then in their highest ascendant.
                                                  --Temple.
   2. (Astrol.) The horoscope, or that degree of the ecliptic
      which rises above the horizon at the moment of one's
      birth; supposed to have a commanding influence on a
      person's life and fortune.
   Note: Hence the phrases
   {To be in the ascendant}, to have commanding power or
      influence, and
   {Lord of the ascendant}, one who has possession of such power
      or influence; as, to rule, for a while, lord of the
      ascendant. --Burke.
   3. Superiority, or commanding influence; ascendency; as, one
      man has the ascendant over another.
            Chievres had acquired over the mind of the young
            monarch the ascendant not only of a tutor, but of a
            parent.                               --Robertson.
   4. An ancestor, or one who precedes in genealogy or degrees
      of kindred; a relative in the ascending line; a
      progenitor; -- opposed to {descendant}. --Ayliffe.
   

2. \As*cend"ant\, Ascendent \As*cend"ent\, a.
   1. Rising toward the zenith; above the horizon.
            The constellation . . . about that time ascendant.
                                                  --Browne.
   2. Rising; ascending. --Ruskin.
   3. Superior; surpassing; ruling.
            An ascendant spirit over him.         --South.
            The ascendant community obtained a surplus of
            wealth.                               --J. S. Mill.
            Without some power of persuading or confuting, of
            defending himself against accusations, . . . no man
            could possibly hold an ascendent position. --Grote.