In general, to append is to join or add on to the end of something. For example, an appendix is a section appended (added to the end) of a document.
In computer programming, append is the name of a procedure for concatenating (linked) lists or arrays in some high-level programming languages.
Prepention – the act of prepending
To attach (an expression, phrase, etc.) to another, as a prefix.
To premeditate; to weigh up mentally.
To hang or attach to, as by a string, so that the thing is suspended
“a seal appended to a record”
“An inscription was appended to the column.”
To add, as an accessory to the principal thing; to annex
“notes appended to a book chapter”
To write more data to the end of a pre-existing file, string, or other non-constant data type.
An instance of writing more data to the end of an existing file.
add (something) to the beginning of something else
“you forgot to prepend ‘I personally believe’ to the statements you are making”
attach (a piece of data) to the beginning of another
“in this case, you must prepend the server name to the database name, separated by a period”
add (something) to the end of a written document
“the results of the survey are appended to this chapter”