adj., pron., adv., & conj.
adj. & pron. (foll. by sing. verb) 1 not the one nor the other (of two things); not either (neither of the accusations is true; neither of them knows; neither wish was granted; neither went to the fair). 2 disp. none of any number of specified things.
adv. 1 not either; not on the one hand (foll. by nor; introducing the first of two or more things in the negative: neither knowing nor caring; would neither come in nor go out; neither the teachers nor the parents nor the children). 2 not either; also not (if you do not, neither shall I). 3 (with neg.) disp. either (I don't know that neither).
conj. archaic nor yet; nor (I know not, neither can I guess).
[ ME naither, neither f. OE nowther contr. of nohwther (as NO(2), WHETHER): assim. to EITHER ]