Definition of sithe:
(v) :
(dialect, dated) To sigh.
(n) :
(obsolete) A sigh.
(v) :
(obsolete) To journey, travel, wayfare.
(n) :
Obsolete form of scythe. [An instrument for mowing grass, grain, etc. by hand, composed of a long, curving blade with a sharp concave edge, fastened to a long handle called a snath.]
(v) :
Obsolete form of scythe. [(intransitive) To use a scythe.]
(n) :
Alternative spelling of sith. [(obsolete) A journey, way.]