Cut the cucumber in half lengthwise and scoop out the seeds. Grate the cucumber and add to a bowl.
Mince the garlic and add to the cucumber.
Mince the dill, removing any stems, and add about 2 tbsp to the cucumber.
Juice the lemon and add to the cucumber mixture.
Add greek yogurt, olive oil, vinegar, salt, pepper, and sugar.
Stir to combine. Chill in fridge until ready to serve.