/n[y]oo'li:n/ Line feed or other character sequence used to terminate a line of text.
Unix uses line feed as its text line terminator - a Bell-Labs-ism rather than a Berkeleyism. Interestingly (and unusually for Unix jargon), it is said to have originally been an IBM usage. Though the term "newline" appears in ASCII standards, it never caught on in the general computing world before Unix. The encoding of line feed as "\n" in C and Unix strings comes from this name.
The term has been used more generally for any end of line character, character sequence (e.g. crlf), or operation (like Pascal's writeln procedure or Lisp 1.5's terpri) required to terminate a text record or separate lines.