Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
nĕcŭbi, adv. [ne alicubi], that nowhere, lest anywhere (not in Cic.). itaque faciunt lapide stratā, ut urina necubi in stabulo consistat, Varr. R. R. 2, 2, 19; so, ut necubi, Col. 2, 18, 4: dispositis exploratoribus, necubi Romani copias transducerent, Caes. B. G. 7, 35; Liv. 22, 2, 3; 25, 33, 9; Suet. Aug. 46; 86; Luc. 9, 1059.