1 - if you will remove all the HTML tags, doesnt need to put $null
2 - if you will use tokenize, why did you use $gettok so? instead using $1 $2 and $3?
3 - you dont need to do a lot of vars like on hhfree alias... just return the value of all the commands
4 - there is no reason to use alias GetDefineSearch when you can do the same command on the on text event
5 - no need to use timers, and then do a noop command just to flood control
6 - whats the reason for the $ticks on $regsubex, if you will not call the $regsubex name after?
7 - you are a newbie, accept the advices
8 - if you want to make it a challenge, we can short it a lot, check my example, shorter and with some modifications

alias -l hhfree {
  return $replace($regsubex($regsubex($1-,/<[^>]+>/g,),/&#(\d+);/g,$chr(\1)),&nbsp;,$chr(32),&quot;,")
}
On $*:Text:/^(!|@)Define.*/Si:#:{
  if ($($+(%,define,$wildsite,$network),2) = 1) { .notice $nick Please wait 6 seconds to trigger this command again. | return }
  else {
    set -u6 $+(%,define,$wildsite,$network) 1 
    var %sockname = $+(define,$network,$2,$ticks)
    sockopen %sockname oxforddictionaries.com 80
    sockmark %sockname $iif($regml(1) == !,.msg $chan,.notice $nick) $2-
  }
}
on *:sockopen:define*:{
  tokenize 32 $sock($sockname).mark
  if (!$sockerr) {
    var %x = sockwrite -nt $sockname
    %x GET $+(/definition/,$3,?q=,$3) HTTP/1.1
    %x Connection: close
    %x Host: $+($sock($sockname).addr,$str($crlf,2))
  }
  else { $1-2 $sock($sockname).addr is having some technical difficulties. }
}
on *:sockread:define*:{
  tokenize 32 $sock($sockname).mark
  if ($sockerr) { $1-2 $sock($sockname).addr is having some technical difficulties. }
  else {
    var %define 
    sockread %define
    if ($regex(%define,/<span class="definition">(.*?)<\/span>/)) { 
      $1-2 Definition: $hhfree($regml(1))
    }
    if ($regex(%define,/<span class="exampleGroup exGrBreak"> <em class="example"> (.*?)<\/em><\/span>/)) {
      $1-2 Example: $hhfree($regml(1)) 
    } 
    if (*Page not found* iswm %define) { 
      $1-2 No Results have been found for: $qt($3) | sockclose $sockname 
    }
  }
}