It is widely believed that apart from ‘yaaskaachaarya’ there happened to be twelve more ‘aachaaryaa’ prior to him who were also specialized in rendering the ‘nirukta’-type of explanation of the originl of Vedic words, but all their works were lost in time and not even a single work of theirs is available today. According to this view, the existence of Vedic dictionaries prior to ‘niruktamu’ is not to be ruled out and hence yaaskaachaarya’s ‘niruktamu’ might not be the first of its kind. It can, therefore, be confidently said that the idea of lexicography had struck the Indian intellect as far back as 8th or 7th Century BC, during which period ‘yaaskaachaarya’ was believed to have lived.
As for the Indian non-Vedic dictionaries are concerned, amarasimha’s ‘amarakoeSamu’ remains till date the earliest in the history, which even though a difference of opinion still exists amongst the scholars regarding the period during which ‘amarasimha’ lived, it is popularly believed that he belonged to the first Century BC. ‘amarasimha’ who is considered to be one of the nine jewels who adorned King Vikramaaditya’s elite assembly along with the likes of mahaakavi kaaLidaasu, compiled the ‘amarakoeSamu’ in three sections consisting of 1499 ‘Sloekaa’. The ‘Sloeka’ format facilitates easy memorizing and for the students who want to learn the Sanskrit language, studying the ‘amarakoeSamu’ and learning it by heart is considered a must. In the good olden days children of very tender age were made to sit in the shades of trees and under the supervision of an experienced guru they were guided to learn the ‘Sloekaa’ one by one by heart, without in the first instance bothering to make the meaning of the ‘Sloekaa’ known while by-hearting the same. By the time the children completed the learning of the entire ‘amarakoeSamu’ by heart and mastered it, they would be much mature and grown up to be explained the meaning of the ‘Sloekaa’, which they were promptly introduced to and explained. This method invented and strictly followed until very recently by the Indian intellect to achieve command over the vocabulary of Sanskrit language has been unique and has found no parallel until today.