1 ' Free ' absolutely means 'free from any sorts constraints or controls. The context determines its different denotations, if any, as in 'free press', 'fee speech', 'free stuff' etc.
Free ride dates back to 1880, while free loader is a more recent construction “freeloader (n.) also free-loader, by 1939, from free (adj.) + agent noun from load (v.)As a verb, freeload is attested by 1967 and probably is a back-formation from this”
I checked Garner's Modern American Usage; although BG doesn't address free of vs. free from, he writes that the distinction between freedom of and freedom from is that the former indicates the "possession of a right" (freedom of speech) and the latter "protection from a wrong" (freedom from oppression). So free from is used to indicate protection from something problematic, and free of (which ...
"Free of" vs. "Free from" - English Language & Usage Stack Exchange
What is the opposite of free as in "free of charge" (when we speak about prices)? We can add not for negation, but I am looking for a single word.
I don't think there's any difference in meaning, although "free of charges" is much less common than "free of charge". Regarding your second question about context: given that English normally likes to adopt the shortest phrasing possible, the longer form "free of charge" can be used as a means of drawing attention to the lack of demand for ...
For free vs. free of charges [duplicate] - English Language & Usage ...
Free entrance X chargeable entrance. Free parking X paid parking. Free service X chargeable service. Free consultation X paid consultation. Free health care X expensive health care. Free toilet X pay toilet. Free fare (in the sense of a free ticket to travel, the opposite can be a paid ticket). Here there is a mentioning of paying a ticket fare.