Ramadan is derived from the Arabic root word ramida or ar-ramad denoting intense scorching heat and dryness, especially the ground. From the same root there is ramadaa, sunbaked sand, and dthe famous proverb: “Kal Mustajeer minar Ramadaa binnar” – to jump out of the frying pan into the fire. And in a hadith the Messenger of Allah peace be upon him said:
“The prayer of repenters is due when the young camel can feel the sun’s heat early in the morning.” (Muslim)
Thus, the word Ramadan is so called to indicate the heating sensation in the stomach as a result of thirst. Others said it is so called because Ramadan scorches out the sins with good deeds, as the sun burns the ground. Some said it is so called because the hearts and souls are more readily receptive to the admonition and remembrance of Allah during Ramadan, as the sand and stones are receptive to the sun’s heat. The framers of this beautiful language may have been inspired by Allah Subhana wa Taa’ala in naming this month Ramadan. Otherwise, the relation between the heat and its properties is miraculously similar to that of Ramadan. While the heat represents the matter that helps shape, form, and mold virtually every matter – from metal and plastics, to plants and living cells – Ramadan undoubtedly helps a serious believer remold, reshape, reform, and renew his physical and spiritual disposition and behaviour.
Reference: T. Shu’aib, Essentials of Ramadan the Fasting Month.