【正确答案】：
EXTENSION OF MEANING, ALSO KNOWN AS GENERALIZATION, IS THE NAME GIVEN TO THE WIDENING OF MEANING WHICH SOME WORDS UNDERGO. IT IS A PROCESS BY WHICH A WORD WHICH ORIGINALLY HAD A SPECIALIZED MEANING HAS NOW BECOME GENERALIZED. IN OTHER WORDS, THE TERM HAS EXTENDED TO COVER A BROADER AND OFTEN LESS DEFINITE CONCEPT. 
【题目解析】：Extension of meaning, also known as generalization, is the name given to the widening of meaning which some words undergo. It is a process by which a word which originally had a specialized meaning has now become generalized. In other words, the term has extended to cover a broader and often less definite concept.