[1] : The Collaborative International Dictionary of English v.0.48

hyacinth \hy"acinth\, n. l. hyacinthus a kind of flower, prob.
   the iris, gladiolus, or larkspur, also a kind of gem, perh.
   the sapphire; as, a proper name, hyacinthus, a beautiful
   laconian youth, beloved by apollo, fr. gr. ?, ?: cf. f.
   hyacinthe. cf. jacinth. the hyacinth was fabled to have
   sprung from the blood of hyacinthus, who was accidentally
   slain by apollo.
   1. bot.
      a a bulbous plant of the genus hyacinthus, bearing
          beautiful spikes of fragrant flowers. hyacinthus
          orientalis is a common variety.
      b a plant of the genus camassia camassia farseri,
          called also eastern camass; wild hyacinth.
      c the name also given to scilla peruviana, a
          mediterranean plant, one variety of which produces
          white, and another blue, flowers; -- called also, from
          a mistake as to its origin, hyacinth of peru.
          1913 webster

   2. min. a red variety of zircon, sometimes used as a gem.
      see zircon.
      1913 webster

   hyacinth bean bot., a climbing leguminous plant
      dolichos lablab, related to the true bean. it has dark
      purple flowers and fruit.
      1913 webster
see also:
jacinth hyacinthus hyacinthus orientalis camassia camassia farseri eastern camass 
scilla peruviana hyacinth of peru zircon hyacinth bean dolichos lablab 

[2] : The Collaborative International Dictionary of English v.0.48

zircon \zir"con\, n. f., the same word as jargon. see jargon
   a variety of zircon.
   1. min. a mineral consisting predominantly of zirconium
      silicate zr2sio4 occurring in tetragonal crystals,
      usually of a brown or gray color. it consists of silica
      and zirconia. a red variety, used as a gem, is called
      hyacinth. colorless, pale-yellow or smoky-brown
      varieties from ceylon are called jargon.
      1913 webster +pjc

   2. an imitation gemstone made of cubic zirconia.
      pjc

   zircon syenite, a coarse-grained syenite containing zircon
      crystals and often also elaeolite. it is largely developed
      in southern norway.
      1913 webster
see also:
jargon zr2sio4 hyacinth jargon cubic zirconia zircon syenite 

[3] : WordNet (r) 2.0

hyacinth
     n 1: a red transparent variety of zircon used as a gemstone syn:
           jacinth
     2: any of numerous bulbous perennial herbs
see also:
jacinth 

Hyacinth >> H Words
Hyacinth, definition of term: Hyacinth
hyacinth_pag1.html

Water Hyacinth >> W Words
Water Hyacinth, definition of term: Water Hyacinth
water+hyacinth_pag1.html