amplify

verb
1
to increase something in strength, especially sound
تقویت کردن, افزایش دادن, بلندتر کردن
2
to add details to a story, statement, etc.
بسط دادن, توضیح دادن, افزودن جزئیات, شرح دادن
She refused to amplify further.
You may need to amplify this point.