(v.) To cut off the end of something. Usually, the term is used to describe a type of rounding of floating-point numbers. For example, if there are too few spaces for a long floating-point number, a program may truncate the number by lopping off the decimal digits that do not fit: 3.14126 might be truncated to 3.14. Note that truncation always rounds the number down. If the number 1.19999 is truncated to one decimal digit, it becomes 1.1, not 1.2.
The term also is used to describe the process of shortening data that is gathered in a dynamic field. For example, an electronic form that asks for a person’s name and only allows for 10 characters will cut off any characters after the 10th even though a person’s name may be more than 10 characters.
The term also is used to describe the process of removing bits when data is moved to a storage medium. For example, an MP3 file might be truncated, or made smaller by removing bits of data, when stored on a compact disc.
Other forms: truncately (adv.) and truncation (n.)