In the Bible, Goliath is a huge, strong fighter. A young shepherd named David kills him with a stone from a sling, and David later becomes king. English took that name and now uses Goliath — often with a capital G, sometimes without — for any person, company, or team that is very large and powerful, especially when a much smaller one stands against it. Newspapers love a David and Goliath story for a little side beating a giant. The word feels a bit dramatic; in ordinary talk people might just say giant or huge company. Though actually, calling someone a Goliath is about size and power. The old story makes Goliath the enemy, but the modern word is mostly the big one. You will hear it in news, sport, and business more often than in everyday chat.