terminator

1. A DNA sequence just downstream of the coding segment of a gene, which is recognized by RNA polymerase as a signal to stop synthesizing mRNA. 2. A term used in GMO technology for a transgenic method which genetically sterilizes the progeny of the planted seed, thereby preventing the use of farm-saved seed.

Transition from sunlight to earth's shadow in space.

A "character" or "string" that marks the end of another string. The variable contains the string that terminates a readline operation, which chomp deletes from the end. Not to be confused with delimiters or separators. The period at the end of this sentence is a terminator.