Necromancy is a related term of spell.
As nouns the difference between necromancy and spell
is that necromancy
is divination involving the dead or death while spell
is (obsolete) speech, discourse or spell
can be (dialectal) a splinter, usually of wood; a spelk or spell
can be a shift (of work); a set of workers responsible for a specific turn of labour.
As a verb spell is
(obsolete) to speak, to declaim or spell
can be (obsolete) to read (something) as though letter by letter; to peruse slowly or with effort or spell
can be to work in place of (someone).