The Free On-line Dictionary of Computing (19 January 2023):

prepend

    /pree'pend'/ (by analogy with "append") To prefix or
   add to the beginning.

   [Jargon File]

   (1998-04-23)


The Jargon File (version 4.4.7, 29 Dec 2003):

prepend
 /pree`pend'/, vt.

    [by analogy with ‘append’] To prefix. As with ‘append’ (but not ‘prefix’ or
    ‘suffix’ as a verb), the direct object is always the thing being added and
    not the original word (or character string, or whatever). “If you prepend a
    semicolon to the line, the translation routine will pass it through
    unaltered.”