The term lo mein comes from the Cantoneselōu mihn (撈麵), meaning “stirred noodles”. The Cantonese usage of the character 撈, pronounced lōu and meaning "to stir", differs from the character's usual meaning of "to dredge" or "to scoop out of water" in Mandarin, in which case it would be pronounced as làauh or lòuh in Cantonese (lāo in Mandarin). In Mandarin, the dish is more typically called bàn miàn (拌麵), not to be confused with bǎn miàn (板麵).
American Chinese cuisine
In American Chinese restaurants, lo mein is a popular take-out food. In this setting, lo mein noodles are usually stirred with a sauce made from soy sauce and other seasonings. Vegetables such as bok choy and cabbage can be mixed in and meats like roast pork, beef or chicken are often added. Shrimp lo mein, lobster lo mein, vegetable lo mein, and "House" lo mein (more than one meat) are sometimes available.
A version sold in many places in western North America is sometimes labeled as chow mein. However, the two are prepared differently, with very different noodles. Chow mein is stir fried, while lo mein is not.