1 kost-gæfa
ð, to push on with a thing; kostgæfa eptirförna, to pursue hard, Ísl. ii. 360; k. undanróðrinn, Fb. i. 396; k. e-s nauðsyn, ii. 91.
2 kost-gæfa
2. to strive, take pains, with infin.; k. at fremja, Bs. i. 42, Magn. 468, Fms. i. 184, vii. 31, Eb. 39 new Ed.:—reflex., H. E. i. 249, Barl. 78.