The tool used to find a similar word in document is called ______?

The tool used to find a similar word in document is called ______?

دستاویز میں ملتے جلتے لفظ کو تلاش کرنے کے لیے استعمال ہونے والے ٹول کو کیا کہا جاتا ہے؟
Explanation

A thesaurus or synonym dictionary is a reference work for finding synonyms and sometimes antonyms of words.