Much more common in evil, old unstructured language featuring line numbers, like BASIC, and with old editors like ed, than in modern times. It is still possible to write spaghetti code in structured languages like C, but this is less common and is discouraged by language features like explicit nesting and functions.

spaghetti code n.

Code with a complex and tangled control structure, esp. one using many GOTOs, exceptions, or other `unstructured' branching constructs. Pejorative. The synonym `kangaroo code' has been reported, doubtless because such code has so many jumps in it.

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.