What does the word "hardt" mean in German?

I have a etymologic search abaot  your last name.There are only 2 answers 
First the word Hardt means Heart.But there are no suitable way to
decline with etymology.
Or Hardt is (Hardt ist der Name) a name.

Gemeinde

    * einer Gemeinde im Westerwaldkreis in Rheinland-Pfalz, siehe:
Hardt (Westerwald)
    * einer Gemeinde im Landkreis Rottweil in Baden-Württemberg,
siehe: Hardt (Schwarzwald)

[Bearbeiten]

Teil einer Gemeinde oder Stadt

    * eines Stadtteils von Mönchengladbach, siehe: Mönchengladbach-Hardt
    * dem Stadtteil von Dorsten in Nordrhein-Westfalen, siehe: Hardt (Dorsten)
    * eines Ortsteils der Gemeinde Großaitingen im Landkreis Augsburg
in Bayern, siehe: Großaitingen-Hardt
    * eines Ortsteils von Gummersbach in Nordrhein-Westfalen, siehe
Hardt (Gummersbach)
    * eines Stadtteils von Nürtingen in Baden-Württemberg, siehe: Hardt (Nürtingen)
    * der Ortsteil von Nümbrecht in Nordrhein-Westfalen, siehe: Hardt (Nümbrecht)
    * der Ortsteil von Radevormwald in Nordrhein-Westfalen, siehe:
Hardt (Radevormwald)
    * der Ortsteil von Wielenbach in Bayern, siehe: Hardt (Wielenbach)

 Hardt is the name of some places in Germany.
http://de.wikipedia.org/wiki/Hardt

I also have some etymologic serach about your Word but there is no
explanation for it.Basicly it can be a version of the word -heart-
which evolates in time as  -hardt-.The most common usage of your name
is as surnames of german people or german originated people.and its
also used as place names.There is also a few place names in other
countries.

There are places that have the name Hardt:

Places
[edit]

In Germany

    * Hardt (Westerwald) , in the Westerwaldkreis district, Rhineland-Palatinate
    * Hardt (Schwarzwald) , in the Landkreis Rottweil district, Baden-Württemberg
    * Mönchengladbach-Hardt , a part of Mönchengladbach
    * Hardt (Dorsten) , a part of Dorsten, North Rhine-Westphalia
    * Großaitingen-Hardt, a part of Großaitingen in the Augsburg district, Bavaria
    * Hardt (Gummersbach) , a part of Gummersbach, North Rhine-Westphalia
    * Hardt (Nürtingen) , a part of Nürtingen in Baden-Württemberg
    * Hardt (Nümbrecht) , a part of Nümbrecht , North Rhine-Westphalia
    * Hardt (Radevormwald) , a part of Radevormwald , North Rhine-Westphalia

[edit]

Other

    * Hardt Forest, a forest north and south of Karlsruhe


http://www.websters-online-dictionary.org/definition/hardt

Scriptor-ga or Politicalguru-ga as native speakers of German will
probably come along and give a correct answer.  Till then, let me try
to explain.

There are several German names that end in "-hardt" or "-hard" or
"-hart", e.g.,  Gerhardt, Burghard (also Burkhart, Burkhardt,
Burckhardt, etc.).  Both these are are first and last names.  Further
last names are Schweighardt, Streichhardt, and others.  And there are
firstnames like Hartmut, Hartmann, and also an old German name for
October: Gilbhard or Gilbhart.

The most frequent meaning of "hardt" (any spelling) is "hard" or "fast":
Gerhardt = a hard speer;  Hartmut = one of fast courage; Burghard = a
mighty fortress.
The following is a Google translation from the site of a German
diocese about its patron saint:
http://www.dioezesankomitee.de/index.php?myELEMENT=61844
"Name meaning
    Burkhard means "hard (firm) castle" (old-high-German).
Name derivatives
    From ' Burkhard ' the following names are derived: Burk, Buggo,
Buko, Busso, Burghild, Burghilde, Bork, Borchard, Borchert, Birk.

Representation
    Burkhard of peppering castle is represented as a bishop with
staff, book and coat of arms."

("Peppering castle"?!  Würzburg:  Würz, Gewürz = spice.  Clever, Google!)  

But "Hart" is also an old word for "woods"; Hartmann is a woodsman,,
and this meaning is the source of the many geographical names "Hardt"
that Demianunique listed.

Gilbhard (which is also a family name) is translated on a site that I
cannot find again:  Gilb = gelb = yellow, hard = much; appropriate for
the season (which may not be etymologically correct, but rather a
broader interpretation of "hart").

So, does that make the first bearer of your name a "bloody hard" chap,
hardy in the face of blood; or someone from a "Blood Forest", which
could have been named after its dominant trees, "Blutbuchen"  Fagus
sylvatica, which has dark redish leaves; or a forest that was the site
of bloody feud or executions; or was he someone who shed much blood  -
others' or his own?

Scriptor, help!  :-)