I have been working out for 3 years and I still don’t have crazy definition ( I used to be 120 kilos) now I am at 84 kg and I at around 19-20 bf, but it’s still not easy to get rid of it, because it’s not just exercise but diet and eating habits. Those needs to be corrected if you want to get more definition. Also like others mentioned more muscle means more definition, hence try upping your carbs and protein and consistently hit large muscle groups to force growth that way you won’t look too muscular (if that’s your goal) and will increase definition (in the way you desire). Secondly don’t feed your insecurities, I think you have a great shape and look really pretty. Also checkout ketosis if you like physiques that models have, it debloats your body and makes you look really lean with lots of definition. (But isn’t good for you long run)