Definition of freethinker. : a person who thinks freely or independently : one who forms opinions on the basis of reason independently of authority; especially : one who rejects or is skeptical of religious dogma.
Even though most German speakers may understand what you mean when you say beamer instead of projector, native English speakers will typically be completely lost. * Evidence for the use of the word beamer for BMW cars and motorbikes can be found in the Oxford English Dictionary, see here. An alternative spelling is beemer. Moreover, as explained here, BMW enthusiasts use beamer/beemer for cars and beamer for motorbikes. (Thanks to Eric for the link.)
Meaning strong horizontal beam is from c.1600. Meaning dormant or inoperative thing is from 1620s. Meaning railroad sleeping car is from 1875. Sense of something whose importance proves to be greater than expected first attested 1892, originally in American English sports jargon, probably from earlier (1856) gambling slang sense of unexpected winning card.