/sith/ , adv., conj., prep. Archaic.
since.
[ bef. 950; ME; OE siththa, dial. var. of siththan, orig., sith tham after that, subsequently to that, equiv. to sith subsequently (akin to Goth seithus, ON sith- late, G seit since) + tham, dat. of demonstrative pronoun, i.e., "to that" (see THE 1 ); cf. ON sithan sith ]