An example of this is the term groovy which is a relic of 1960's and 70's American hippy slang. Nevertheless, for a slang term to become a slang term, people must use it, at some point in time, as a way to flout standard language.
Cycling is a highly effective form of exercise. It requires a lot of energy, builds lean muscle mass, and improves your strength, cardio capacity and endurance. However, cycling won't specifically burn belly fat. It will certainly help to reduce your overall body fat, but since spot reduction is a myth, you will have to be patient for your belly fat to burn off with the rest of your fat.
Female fat distributions. Progesterone & estrogen both play a role in keeping the waist of women smaller. This is because estrogen works against the action of insulin (and testosterone is a belly fat storing hormone in women) while both estrogen and progesterone oppose the action of cortisol. Insulin and cortisol, together with testosterone and low estrogen, are implicated in belly fat deposition in women.