While there is no other info to go with the name, it could very well stand for a new, upcoming compact crossover that would exist as an entry-level vehicle under the F-Pace, E-Pace and the electric I-Pace (which is easily differentiated from the non-electric E-pace, as the I-Pace doesn't use internal combustion).
Australia's CarAdvice suggests the eventual range-topping Pace model would be called the J-Pace, to go along with the XJ nameplate that's formed an upscale backbone for Jaguar for decades. As for sedans, the XE is paired with the E-Pace, and the F-Pace corresponds to the XF; with Volvo's crossover versions already reserving the XC name, there's no chance for Jaguar to have a matching C-Pace and XC combination in its portfolio. The C-Pace could also be a crossover coupe version based on either the E-Pace or the F-Pace.
The trademark application was filed on July 9, and along with car-related goods and services, the application also covers software and charging stations, even buildings. We'll keep an eye on it.