Exclude Taxonomy From WordPress Post Type

Paste Before If condition of while loop

query_posts( array(

    'post_type' =>'videos',

    'tax_query' => array(

        array(

            'taxonomy' => 'video_cats',

            'field'  => 'slug',

            'terms'  => array( 'adult' ),

            'operator' => 'NOT IN',

        ),

    )

) );