I agreed with Peniston Booth, '
roger wilco' military use is wrong. It's a tautology i.e. uselessly repetitive. That's also true in any formal radio telephone procedure such as in police RT where they're not used together. In aviation use neither
roger nor wilco are even used much as individual
words. The full meaning of
roger is 'Your last message is received and understood' and it's origin indeed as stated by schizzy is the original phonetic alphabet use of
roger for the letter 'R' to 1951now romeo . The full meaning of 'wilco' is 'Your last message is received and understood AND wilL BE coMPLIED WITH'. Therefore wilco already includes
roger.
However, this being Urban
Dictionary it's the slang/colloquial use being defined so in that setting schizzy's example of the
wife/husband is correct whether speaking directly or by phone. It'd also be very acceptable if they were using CB radio I guess. It's slang use can even have slightly sarcastic or facetious overtones at times. However, having an aviation background I reject his example of the pilot and ATC. Redundancy is the lesser sin, no pilot should answer like that. It's required to repeat the instruction back to the controller. The instruction wouldn't be given verbatim as quoted anyway. In aviation, the use of
roger to acknowledge information no instructions may be acceptable at times but wilco is rarely used if at all. Mostly where
roger could be used it's sufficient to simply answer with the aircraft's call sign.
In a casual 'slang' conversation:
Wife: 'Please pick up the
paper off the driveway when you come home tonight'
Husband:
Roger wilco. Your wish is my command!