Charak Samhita
करणंपुनस्तद्यदुपकरणायोपकल्पतेकर्तुःकार्याभिनिर्वृत्तौप्रयतमानस्य ॥७०॥
॥ Karana (means or equipments)॥ Karana is that which serves as means or equipment for the karana (doer) making effort for performing the action.
english translation
karaNaMpunastadyadupakaraNAyopakalpatekartuHkAryAbhinirvRttauprayatamAnasya ॥70॥
hk transliteration by Sanscript