It is possible, but it depends on how you define a "word". If we just keep it simple and say a word is separated by spaces (these look like names though, not words, which can get tricky***) then you could do something like this:
$tags = explode('-',$row_IncidentLookup['OutCome']);
foreach($tags as $key) {
$words = explode(' ', $key); //Separate by space like I mentioned above
echo '<span class="class">'.$words[0].' '.$words[1].'</span>'.implode(' ', array_slice($words, 2)).'<br />';
}
Note the above is not tested so I may have made a mistake, but you probably get the general idea: you split up the $key variable by spaces to find the first two, and then remove those two from the array before putting them back together again (so you're not repeating them) into a string. Check out [man]array_slice/man for more info.
*** The reason names can be tricky is not all names are separated by spaces or are "one word". For example a lot of last names have multiple words like "van Gogh" (Vincent van Gogh, the famous painter). While these may be a minority they should still be considered.
