What is the exact significance of the terms अर्गला and कीलक as they appear in qualifying several mantras, stotras etc? I have seen these terms, but did not think further about them. Someone asked me this question, and I did not have an answer.

Madhav M. Deshpande

Professor Emeritus, Sanskrit and Linguistics

University of Michigan, Ann Arbor, Michigan, USA

Senior Fellow, Oxford Center for Hindu Studies

[Residence: Campbell, California, USA]