Source : Webster's Revised Unabridged Dictionary (1913)

Understand \Un`der*stand"\ ([u^]n`d[~e]r*st[a^]nd"), v. t. [imp.
   & p. p. {Understood}, and Archaic {Understanded}; p. pr. &
   vb. n. {Understanding}.] [OE. understanden, AS. understandan,
   literally, to stand under; cf. AS. forstandan to understand,
   G. verstehen. The development of sense is not clear. See
   {Under}, and {Stand}.]
   1. To have just and adequate ideas of; to apprehended the
      meaning or intention of; to have knowledge of; to
      comprehend; to know; as, to understand a problem in
      Euclid; to understand a proposition or a declaration; the
      court understands the advocate or his argument; to
      understand the sacred oracles; to understand a nod or a
      wink.