Comparative evidence

ḱek, ḱekʷ

• OInd. śak- 'be able' (Whitney 1885: 169); ''be strong', 'be powerful', 'be capable' (of), 'be competent' (for); 'exert one's self for another', 'aid', 'help', 'assist'; Pass. 'be overcome', 'be subdued', 'succumb'; 'yield', 'give way'; 'be compelled', 'be caused' (to do smth.); 'be able', 'be capable', 'be possible', 'be practicable' (with an inf. in pass. sense, e.g. tat kartuṁ śakyate, "that can be done")  (MW: 1044)

References

MW = Monier-Williams, M. 1899. A Sanskrit-English Dictionary. Clarendon Press.
Whitney 1885 = Whitney W. D. 1885. The roots, verb forms and primary derivatives of the Sanskrit language. A supplement to his Sanskrit grammar. Leipzig.