The Jargon File (version 4.4.7, 29 Dec 2003):

nanoacre
 /nan'oh?ay`kr/, n.

    A unit (about 2 mm square) of real estate on a VLSI chip. The term gets its
    giggle value from the fact that VLSI nanoacres have costs in the same range
    as real acres once one figures in design and fabrication-setup costs.


The Free On-line Dictionary of Computing (30 December 2018):

nanoacre

    /nan'oh-ay"kr/ A unit (about 2 mm square) of
   real estate on a VLSI integrated circuit.  VLSI nanoacres
   have costs in the same range as real acres once one allows for
   design and fabrication setup costs.

   [Jargon File]

   (1995-09-20)