Comparative evidence

keu̯p

• OInd. kup- 'be angry' (Whitney 1885: 20); 'be moved', 'be excited', 'be agitated'; 'swell', 'heave', 'boil' (with rage or emotion) (MW: 291)

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.