Under-delfan

According to the Old English Dictionary:

under-delfan

to dig under, undermine dig out (lit. or fig.) :-- Ic underdelfe subfodio, Ælfc. Gr. 28, 6; Zup. 179, 11. Æt dura hé under-delfeþ (suffodiet) fótwylmas ðíne, Scint. 196, 8. Ðú beswice oððe underdulfe (supplantasti) onárísende on mé under mé, Ps, Lamb. 17, 40. Seáþ hé geopnode and hé underdealf ðæne lacum aperuit et effodit eum, 7, 16. Hé nolde geþafigan ðæt man hys hús underdulfe non sineret perfodi domum suam, Mt. Kmbl. 24, 43: Lk. 12, 39. Hé nolde geþafian ðam þeófe náteshwón ðæt hé underdulfe dígellíce his hús, Homl. Ass. 50, 13. Ne beóþ underdolfene l ne beóþ forscræncte stæpas his non supplantabuntur gressus ejus, Ps. Lamb. 36, 31. ¶ underdelfan glosses suffocare, Mt. Kmbl. Lind. 13, 7, 22: Mk. Skt. Lind. Rush. 4, 7, 19. under-delfan