Shahelm

$groupMakesByWord = array();

foreach ($makes as $make) {
    $groupMakesByWord[$make['word']][] = $make;
}

foreach ($groupMakesByWord as $makeWord => &$makes) {
    uasort($makes, function($a, $b) {
        if ($a['max_bid'] == $b['max_bid']) {
            return 0;
        }

        return $a['max_bid'] < $b['max_bid'] ? 1 : -1;
    });
}

unset($makes);

$result = array();

foreach ($groupMakesByWord as $makes) {
    $result[] = current($makes);
}