Where did 양배추 and 양상추 come from?

ANSWER: from the West

The Chinese character 洋 (양) means sea or ocean, but it can also mean foreign and is usually used to describe things from Western foreign countries, which Koreans refer to as 서양국 (西洋國) or simply 서양 (西洋). When 양 (洋) is attached to the beginning of a Korean word, it usually means "Western-style." Here are some examples:

• 양궁 - Western-style archery
• 양동이 - Western-style jar or metal bucket
• 양말 - Western-style socks
• 양배추 - Western-style cabbage
• 양복 - Western-style clothes or suit
• 양산 - [Western-style] umbrella
• 양상추 - Western-style lettuce
• 양식 - Western-style food
• 양악 - Western-style music
• 양약 - Western-style medicine
• 양옥 - Western-style house
• 양주 - Western-style alcohol
• 양초 - Western-style candle
• 양탄자 - Western-style blanket or carpet

Besides the words listed above, there were many other words used to describe Western-style things when Korea first opened up to the West, but most of those words are now no longer used or rarely used, including 양표 (洋表), which literally means "Western-style (洋) display (表)" but referred to a clock or watch. Another word that is rarely used anymore is 양코배기, which essentially means big-nosed Westerner.

배추

양배추

상추

양상추