- Amarasimha (अमरlसंह) was a Sanskrit grammarian and poet from ancient India. - He is renowned as the author of the 'Amarakosha' (अमरकोश), which is a celebrated thesaurus or lexicon in Sanskrit. - The Amarakosha is organized thematically and is structured as verses to aid memorization. - Amarasimha is traditionally placed in the court of Chandragupta II (Vikramaditya), who ruled during the Gupta period (around 4th-5th century CE).