specific

Explicit or definite.

Pertaining to a species, as a taxon or taxa at the rank of species.

Special, distinctive or unique.

intended for, or applying to, a particular thing.

Serving to identify a particular thing (often a disease or condition), with little risk of mistaking something else for it.

Being a remedy for a particular disease on a deeper level, rather than just masking the symptoms

Limited to a particular antibody or antigen.

Of a value divided by mass (e.g. specific orbital energy).

Similarly referring to a value divided by any measure which acts to standardize it (e.g. thrust specific fuel consumption, referring to fuel consumption divided by thrust)

A measure compared with a standard reference value by division, to produce a ratio without unit or dimension (e.g. specific refractive index is a pure number, and is relative to that of air).