<admin>
    <routers>
      <sphinxsearch>
        <use>admin</use>
        <args>
          <module>AD_SphinxSearch</module>
          <frontName>sphinxsearch</frontName>
        </args>
      </sphinxsearch>
    </routers>
  </admin>

<admin>
     <routers>
        <adminhtml>
            <args>
                <modules>
                    <ad_sphinxsearch before="Mage_Adminhtml">AD_SphinxSearch_Adminhtml</ad_sphinxsearch>
                </modules>
            </args>
        </adminhtml>
    </routers>
</admin> 

And in adminhtml.xml file there are lot of issue. syntax is not proper

  <adminhtml>
    <!-- define menu -->
    <menu>
      <sphinxsearch module="sphinxsearch">
        <title>SphinxSearch</title>
        <sort_order>100</sort_order>
        <children>
          <wordforms module="sphinxsearch">
            <title>wordforms Page Title</title>
            <sort_order>0</sort_order>
            <action>adminhtml/stopwords</action>
          </wordforms>
          <stopwords module="sphinxsearch">
            <title>stopwords Page Title</title>
            <sort_order>0</sort_order>
            <action>adminhtml/stopwords</action>
          </stopwords>
        </children>
      </sphinxsearch>
    </menu>
    <acl>
      <resources>
        <all>
          <title>Allow Everything</title>
        </all>
        <admin>
          <children>
            <sphinxsearch translate="title" module="sphinxsearch">
              <title>SphinxSearch</title>
              <sort_order>1000</sort_order>
              <children>
                <wordforms translate="title">
                <title>Wordforms Page Title</title>
                </wordforms>
                <stopwords translate="title">
                <title>Stopwords Page Title</title>
                </stopwords>

              </children>
            </sphinxsearch>
          </children>
        </admin>
      </resources>
    </acl>
  </adminhtml>