Blended words describe modern life. 'Smog', the haze over big cities, fuses which two words?

"Smog" blends "smoke" and "fog" into a single word describing the hazy, polluted air that hangs over industrial or heavily trafficked cities. This kind of word is called a portmanteau — two existing words fused together, with each contributing both sound and meaning to the new hybrid term.

"Frog" and "small" are unrelated to the word's actual origin and would produce meaningless or nonsensical blends, since smog specifically describes air pollution resembling a mixture of smoke particles suspended in fog-like moisture, not anything to do with amphibians or size.

Portmanteau words are especially common for describing modern phenomena that didn't exist before industrialization, alongside classics like "brunch" (breakfast + lunch) and "motel" (motor + hotel), showing how English efficiently names new concepts by recombining familiar pieces.