The Collaborative International Dictionary of English v.0.48:

Cypress \Cy"press\ (s?"pr?s), n.; pl. Cypresses (-?z). [OE.
   cipres, cipresse, OF. cipres, F. cypr?s, L. cupressus,
   cyparissus (cf. the usual Lat. form cupressus), fr. Gr. ????,
   perh. of Semitic origin; cf. Heb. g?pher, Gen. vi. 14.] (Bot)
   A coniferous tree of the genus Cupressus. The species are
   mostly evergreen, and have wood remarkable for its
   durability.
   [1913 Webster]

   Note: Among the trees called cypress are the common Oriental
         cypress, Cupressus sempervirens, the evergreen
         American cypress, Cupressus thyoides (now called
         Chamaecyparis sphaeroidea), and the deciduous
         American cypress, Taxodium distichum. As having
         anciently been used at funerals, and to adorn tombs,
         the Oriental species is an emblem of mourning and
         sadness.
         [1913 Webster]

   Cypress vine (Bot.), a climbing plant with red or white
      flowers (Ipot[oe]a Quamoclit, formerly Quamoclit
      vulgaris).
      [1913 Webster]

WordNet (r) 3.0 (2006):

cypress
    n 1: wood of any of various cypress trees especially of the
         genus Cupressus
    2: any of numerous evergreen conifers of the genus Cupressus of
       north temperate regions having dark scalelike leaves and
       rounded cones [syn: cypress, cypress tree]