Comparative evidence

ḱenk

• OInd. śaṅk- 'doubt' (Whitney 1885: 170); 'be anxious', 'be apprehensive', 'be afraid' (of), 'fear', 'dread', 'suspect', 'distrust'; 'be in doubt', 'be uncertain' (about), 'hesitate'; 'think probable', 'assume', 'believe', 'regard as', 'suppose to be'; (in argumentative works) 'ponder' (over), 'propound a doubt', propound an objection' (MW: 1047)

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.