Get term by name

$tax_query = array(
	'relation' => 'OR',
	array(
		'taxonomy'         => 'product_tag',
		'terms'            => '$name',
		'field'            => 'name',
	),
	array(
		'taxonomy'         => 'category',
		'terms'            => '$name',
		'field'            => 'name',
	),
	array(
		'taxonomy'         => 'Product_cat',
		'terms'            => '$name',
		'field'            => 'name',
	),
	array(
		'taxonomy'         => 'post_tag',
		'terms'            => '$name',
		'field'            => 'name',
	),
);