$pages = get_posts(array(
'post_type' => 'page',
'numberposts' => -1,
'tax_query' => array(
array(
'taxonomy' => 'taxonomy-name',
'field' => 'term_id',
'terms' => 1, /// Where term_id of Term 1 is "1".
'include_children' => false
)
)
));