资料来源 : Webster's Revised Unabridged Dictionary (1913)

Welcome \Wel"come\, a. [OE. welcome, welcume, wilcume, AS.
   wilcuma a welcome guest, from wil-, as a prefix, akin to
   willa will + cuma a comer, fr. cuman to come; hence,
   properly, one who comes so as to please another's will; cf.
   Icel. velkominn welcome, G. willkommen. See {Will}, n., and
   Come.]
   1. Received with gladness; admitted willingly to the house,
      entertainment, or company; as, a welcome visitor.

            When the glad soul is made Heaven's welcome guest.
                                                  --Cowper.

   2. Producing gladness; grateful; as, a welcome present;
      welcome news. ``O, welcome hour!'' --Milton.

   3. Free to have or enjoy gratuitously; as, you are welcome to
      the use of my library.

   Note: Welcome is used elliptically for you are welcome.
         ``Welcome, great monarch, to your own.'' --Dryden.

   {Welcome-to-our-house} (Bot.), a kind of spurge ({Euphorbia
      Cyparissias}). --Dr. Prior.

Tithymal \Tith"y*mal\, n. [L. tithymalus a plant with a milklike
   sap, Gr. ?: cf. F. tithymale.] (Bot.)
   Any kind of spurge, esp. {Euphorbia Cyparissias}.

资料来源 : WordNet®

Euphorbia cyparissias
     n : Old World perennial having foliage resembling cypress;
         naturalized as a weed in the United States [syn: {cypress
         spurge}]