To tell someone to 'fick off' is essentially telling them to 'fuck off' albeit you typed it wrong because of old age.
Similar in principle to spelling 'Team' with a 'Y', then attempting to pass it off as the Liberian spelling of the word.
Andrea gave Susie a leaflet for the weekly senior citizens aerobics class at the Leisure Centre on Wednesday mornings. For some time Susie had assumed Andrea was being friendly. She was not a senior citizen, she definitely did not mutter 'fick-off' under her breath as she walked off in her leopard skin bra.
German expression meaning "fuck off" or just "fuck you", literally "fuck your knee". The origin of this expression is a pun with the archaic word "Kniefiez", meaning a very avaricious person such as Scrooge McDuck. Therefore, its original meaning was "If you're to cheap for that, you can go and fuck yourself.". However, with time it has become a more general expression that could be used equally well in any other context.
100 Mark für einmal kurz blasen? Fick dichins Knie!