Can parachute itself be the source of the
prefix "para-" in these words?
Yes, in one of them. It is in the case of parabrake.
parabrake (ˈpærəˌbreɪk Pronunciation for parabrake )
noun another name for brake parachute
The word is a clear derivation from the longer term.
However this is not directly so for paraglider.
Origin of paraglider para(foil) + glider.
The American Heritage® Dictionary of the English Language, 5th edition
Paraglider comes from parafoil which, in turn comes from parachute.
Definition of PARAFOIL : a self-inflating fabric device that
resembles a parachute, behaves in flight like an airplane wing, is
maneuverable, is capable of landing a payload at slow speed, and can
be launched from the ground in a high wind like a kite
The scope of the question is to investigate whether grammarians
recognize only two roots for the para-words, or, instead, they
recognize three roots, the last one evolved independently in modern
I think so, yes. For example we often see news items with "-gate" appended to them. Here is a discussion of the phenomenon:
The ‘gate’ suffix
- In 1972 the United States was transfixed by the revelation that the
burglary at the national headquarters of the Democratic Party was
connected with Richard Nixon’s Republican government. The burglary
took place in the Watergate building, Washington DC, and thus, by
metonymy, the scandal itself became known by the name of Watergate.
One of the most significant episodes in modern US politics, Watergate
has since reshaped the language of scandal and controversy in a format
that also extends beyond English-speaking commentaries.*
By Eleanor Maier, OED
You can see that this article was written by an employee of the Oxford English Dictionary - an authoritative source if ever there was one.
Clearly there was nothing about the suffix "gate" that indicated scandal before Watergate. So I think it is safe to say that the etymology of all such scandals is derived from the name Watergate rather than from the word 'gate'.
In the same way it is clear that "para" does not directly mean "be prepared" when it is used in 'paraglider'. The word 'parachute' is the origin via parafoil.
However, when we come to 'parabrake', it could be argued either way. A parabrake may be used in an emergency and hence be a sign of preparedness. However in general parabrakes are used routinely, e.g. to slow down drag racers, re-entering space-craft and so on. They are primarily brakes rather than emergency equipment.
I think it safe to say that 'para' in parabrake derives directly from parachute and not from a Latin or Greek root. However in paraglider the etymology comes via parafoil which is itself a derivation from parachute.