to be at home on any subject

Home \Home\ (h[=o]m; 110), n. [OE. hom, ham, AS. h[=a]m; akin to
   OS. h[=e]m, D. & G. heim, Sw. hem, Dan. hiem, Icel. heimr
   abode, world, heima home, Goth. haims village, Lith.
   k["e]mas, and perh. to Gr. kw`mh village, or to E. hind a
   peasant; cf. Skr. ksh[=e]ma abode, place of rest, security,
   kshi to dwell. [root]20, 220.]
   1. One's own dwelling place; the house in which one lives;
      esp., the house in which one lives with his family; the
      habitual abode of one's family; also, one's birthplace.
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            The disciples went away again to their own home.
                                                  --John xx. 10.
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            Home is the sacred refuge of our life. --Dryden.
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            Home! home! sweet, sweet home!
            There's no place like home.           --Payne.
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   2. One's native land; the place or country in which one
      dwells; the place where one's ancestors dwell or dwelt.
      "Our old home [England]." --Hawthorne.
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   3. The abiding place of the affections, especially of the
      domestic affections.
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            He entered in his house -- his home no more,
            For without hearts there is no home.  --Byron.
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   4. The locality where a thing is usually found, or was first
      found, or where it is naturally abundant; habitat; seat;
      as, the home of the pine.
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            Her eyes are homes of silent prayer.  --Tennyson.
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            Flandria, by plenty made the home of war. --Prior.
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   5. A place of refuge and rest; an asylum; as, a home for
      outcasts; a home for the blind; hence, esp., the grave;
      the final rest; also, the native and eternal dwelling
      place of the soul.
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            Man goeth to his long home, and the mourners go
            about the streets.                    --Eccl. xii.
                                                  5.
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   6. (Baseball) The {home base}; as, he started for home.
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   {At home}.
      (a) At one's own house, or lodgings.
      (b) In one's own town or country; as, peace abroad and at
          home.
      (c) Prepared to receive callers.

   {Home department}, the department of executive
      administration, by which the internal affairs of a country
      are managed. [Eng.]

   {To be at home on any subject}, to be conversant or familiar
      with it.

   {To feel at home}, to be at one's ease.

   {To make one's self at home}, to conduct one's self with as
      much freedom as if at home.

   Syn: Tenement; house; dwelling; abode; domicile.
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