Some terms that I never knew the origin of:
Roger is a current radiotelephony ‘proword’ which is a word used to represent a longer phrase.
Roger means, very specifically: “your message has been received and understood.”
Wilco means: “your message has been received and understood and I will comply.”
Affirm (note, NOT affirmative) simply means yes, but is clearer over the radio.
Negative means no.
Over means I’ve finished speaking and expect a reply.
Out means I’ve finished speaking and do NOT expect a reply.
Roger Wilco over and out means I am not a pilot.