お水は氷なしでいただけますか？ — Could I please have water without ice? (Restaurant · Izakaya, Formal — to staff, JLPT N4)

Gesture & etiquette

Hand gesture indicating 'no' or shaking head slightly while pointing to a glass.

Be aware that in some establishments, cold tap water might be the only option. Asking for 'room temperature' water (常温の水: jōon no mizu) is also an option but less common for just tap water.