sira

As a proper noun sire

is .

As a noun sira is

must (fruit juice that will ferment or has fermented, usually grapes).

As nouns the difference between sir and sira

is that sir is a man of a higher rank or position while sira is a traditional Muslim biography of Muhammad.

As a verb sir

is to address (someone) using "sir".

As an initialism SIR

is surface insulation resistance