In two films about the Titanic, Murdoch was portrayed shooting passengers and himself during the sinking; this was based on a number of eyewitness testimonies of a shooting/suicide by an officer during the launching of the last lifeboat. It is possible that Murdoch was the officer.
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.
(grammar) The form of an adjective that expresses which of several items has the highest degree of the quality expressed by the adjective; in English, formed by appending -est to the end of the adjective (for some short adjectives only) or putting most before it.