What is "to reach at"

Reach \Reach\, v. i.

1. To stretch out the hand.

   Goddess humane, reach, then, and freely taste!
   --Milton.

2. To strain after something; to make efforts.

   Reaching above our nature does no good.
   --Dryden.

3. To extend in dimension, time, amount, action, influence, etc., so as to touch, attain to, or be equal to, something.

   And behold, a ladder set upon the earth, and the top of it reached to heaven.
   --Gen. xxviii. 12.

   The new world reaches quite across the torrid zone.
   --Boyle.

4. (Naut.) To sail on the wind, as from one point of tacking to another, or with the wind nearly abeam.

   To reach after or To reach for or To reach at, to make efforts to attain to or obtain.

   He would be in the posture of the mind reaching after a positive idea of infinity.
   --Locke.