Definition of "Extension" :

noun: act of expanding in scope; making more widely available

"Extension of the program to all in need."

noun: act of stretching or straightening out a flexed limb

noun: an educational opportunity provided by colleges and universities to people who are not enrolled as regular students

noun: an addition that extends a main building

noun: an addition to the length of something

noun: an additional telephone set that is connected to the same telephone line

noun: amount or degree or range to which something extends

"The wire has an extension of 50 feet."

noun: the ability to raise the working leg high in the air

"The dancer was praised for her uncanny extension."

noun: the most direct or specific meaning of a word or expression; the class of objects that an expression refers to

"The extension of satellite of Mars' is the set containing only Demos and Phobos."

noun: the spreading of something (a belief or practice) into new regions

noun: a string of characters beginning with a period and followed by one or more letters; the optional second part of a PC computer filename

"Most applications provide extensions for the files they create."

noun: a mutually agreed delay in the date set for the completion of a job or payment of a debt

"They applied for an extension of the loan."