Curiously the root of that word is 'to search again', meaning more like 'reviewing sources in the library' and less like 'doing experiments in the lab'.
re- in this case is probably an intensive prefix rather than indicating repetition. this is an uncommon re- in english, but does occur, for example in 'refried beans', a calque from spanish where intensive re- is still a productive prefix
so it probably means 'search really hard' rather than 'search again'
