As Legend has already commented, the sources you are using for your study are hardly professional. (Mike Burke's articles, for example, show an obvious lack of training in both Greek and English grammar.) If you really want to know whether a particular translation of a word is viable, then you should consult some of the more advanced works written by men who spent their entire lives studying the language in question. In this particular scenario, I would recommend that you go to your local public library and ask if they have either an Arndt and Gingrich Greek Lexicon (available on amazon for $13) or an unabridged Liddell and Scott Greek Lexicon ($150 on amazon). For Hebrew, you could try the Theological Wordbook of the Old Testament ($32 on amazon).
Whatever source you decide to use, it would be wise to ensure that your copy of the material has not been abridged in any way. Unfortunately, this usually rules out any of the online lexicons.