delimiter

[dih-lim-i-ter]

noun Computers.

a blank space, comma, or other character or symbol that indicates the beginning or end of a character string, word, or data item.

Origin of delimiter

First recorded in 1960–65; delimit + -er¹

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Transcriber's Note: Italics in the text are indicated by the use of an underscore as delimiter, thusly.
The Life of John Sterling
Thomas Carlyle

1960, in computing, agent noun from delimit.