Apte Sanskrit-English Dictionary
a. 1 Not to be transgres- sed, overcome &c.; Śi. 3. 64.
2 Be- yond the reach of, impossible to be done; Ki. 13. 7.
3 Difficult to se- cure or attain, unattainable; Ki. 10. 6, 13; Śi. 8. 57; ºtā state of being proof against an attack or injury; Ki. 11. 63.