The verb establish implies making something new more stable and enduring. The verb enact also creates permanence, but it does so primarily via legislation. To enact something is to make it into law—in fact, bills introduced by Congress begin with the phrase “Be it enacted.” Drawing on a different sense of act, enact can also mean to represent on or as on the stage, as in a performer who is enacting Hamlet. But in the saga of the English language, this sense plays merely a supporting role.
The verbs get and obtain both imply gaining possession of something. But obtain suggests more effort toward that end. For instance, you might hear of information or permission being obtained after having been sought out or requested. This is not always the case with the verb get, which sometimes implies no effort. For instance, that lucky friend who will get the perfect birthday present from you may be blissfully unaware of how difficult it was to obtain!
Something that is spurious is not genuine, authentic, or true. The particular brand of falsehood implied by this slippery adjective depends on what it is describing. When describing objects, such as an artifact or a document, spurious means counterfeit or forged. When describing accusations or claims, spurious veers more toward deliberately misleading or insincere. And when applied to reasoning, as in a spurious argument or spurious correlations, spurious means something closer to faulty or flawed.