Pronunciation: [θˈʌndəklˌa͡ʊd] (IPA) 
The word "thundercloud" is spelled with a "th" sound at the beginning, represented phonetically as /θ/. This sound is made by placing the tongue between the teeth and blowing out air. The "under" part is pronounced with a short "u" sound, as in "hut", represented as /ʌ/. The final syllable "-cloud" is pronounced with a long "ow" sound, as in "how", represented as /aʊ/. So, altogether, the word is spelled as /ˈθʌndərˌklaʊd/.
A thundercloud is a type of cloud characterized by its ability to produce thunder, lightning, and potentially heavy precipitation. It is typically large, dense, and a towering formation, often reaching considerable heights in the atmosphere. Thunderclouds are primarily classified as cumulonimbus clouds, which are associated with intense weather phenomena and are regarded as the largest and most powerful type of cumulus cloud.
These clouds form when warm, moist air rises rapidly in an unstable atmospheric condition, enabling the formation of towering clouds that often have a distinctive anvil-shaped top. Within thunderclouds, strong updrafts carry water droplets upward, causing them to freeze and form ice crystals. As the droplets and ice crystals ascend, they collide and coalesce, creating electrical charge separation that generates lightning.
As thunderclouds grow in size, they can reach heights of several kilometers, with their upper regions often filled with tremendous amounts of ice particles. These particles interact within the cloud, causing friction and static electricity buildup that results in the discharge of lightning bolts, thunder, and occasionally hail. Thunderclouds can also produce heavy rainfall, sometimes in the form of intense downpours or severe storms.
Due to their potential to generate severe weather events and hazards, thunderclouds are closely monitored by meteorologists, and their development and movement are of great interest for predicting severe thunderstorms, tornados, and other hazardous conditions.
The word "thundercloud" is a compound word composed of two separate words: "thunder" and "cloud".
The word "thunder" dates back to the Old English word "thunor", which is derived from the Germanic word "thunraz". This Germanic word is ultimately connected to the Proto-Indo-European root "tonitru", meaning "thunder".
The word "cloud" also has Old English origins, derived from the word "clud" and related to the Old High German word "klot". Both stem from the Proto-Germanic word "kludiz" and the Proto-Indo-European root "kleud", meaning "to hear" or "to listen".
Thus, when combined, "thundercloud" simply refers to a cloud associated with the presence of thunder or a storm.
