I asked this question on stackoverflow, and got put on hold; rightfully so. I hope this is a better place.
Are there applications, desktop applications, plugins, libraries, etc., dedicated to removing the drudgery of copy/pasting from accessing your favorite online dictionary? So you can merely click once on a word in your pdf and instantly see the relevant definition; dismiss it easily, too.
It would be a great help in studying foreign languages; somebody must have thought of that already :)
I am particularly interested in Spanish-English dictionaries. I am also a programmer, so links on something highly technical are welcome, too.