special

added to a regular schedule

“a special holiday flight”

for a special service or occasion

“a special correspondent”

first and most important

“his special interest is music”

surpassing what is common or usual or expected

“he paid especial attention to her”

unique or specific to a person or thing or category

“the special features of a computer”

having a specific function or scope

“a special (or specific) role in the mission”

adapted to or reserved for a particular purpose

“a special kind of paint”

a dish or meal given prominence in e.g. a restaurant

a special offering (usually temporary and at a reduced price) that is featured in advertising

“they are having a special on pork chops”

a television production that features a particular person or work or topic

“the last of a series of BBC specials on Iran is being shown tonight”