Dumb Question

[rarson]

Okay, please forgive me, but I think I don't understand.

I was under the impression, from reading on this forum, that turbocharger compression was adiabatic, because it heats the air up as it compresses.

Then I read about Smokey Yunick's adiabatic engine (which I had never seen before) which seems to imply that heat is neither gained nor lost. Dictionary.com give this definition: "occurring without loss or gain of heat."

I swear I'm not stupid, but can someone explain this to me? I have a feeling that it's got to do with the system as a whole, but I must admit I don't fully understand the usage of the same word in these two situations.