Is it farther or further?
1630s, "having a special quality," from French spécifique, from Late Latin specificus "constituting a species," from Latin species "kind, sort" (see species). Earlier form was specifical (early 15c.). Meaning "definite, precise" first recorded 1740.
specific spe·cif·ic (spĭ-sĭf'ĭk)
Relating to, characterizing, or distinguishing a species.
Intended for, applying to, or acting on a specified thing.
Designating a disease produced by a particular microorganism or condition.
Having a remedial influence or effect on a particular disease.
In immunology, having an affinity limited to a particular antibody or antigen.