The Chinese word for plain is
平原

píng yuán

Chinese Definition

plain
1. 名词. 平原
Components
平
1. level; even; flat
平放 (píng fàng) - to put horizontally
平原 (píngyuán) - plain
馬路很平。 (Mǎlù hěn píng.) - The road is very flat.
2. equal; fair
平分 (píngfēn) - to divide evenly
持平 (chípíng) - impartial
Synonyms: 均
3. equal
平輩 (píngbèi) - same generation
平起平坐 (píngqǐpíngzuò) - to be on an equal footing
平了世界紀錄 (píng le shìjiè jìlù) - equalled a world record
雙方打成五平。 (Shuāngfāng dǎ chéng wǔ píng.) - They reached 5-5.
4. to level; to make level
5. calm; peaceful
太平 (tàipíng) - peaceful and tranquil
風平浪靜 (fēngpínglàngjìng) - to have no waves
心平氣和 (xīnpíngqìhé) - even-tempered and good-humoured
Synonyms: 穩, 靜
6. to calm down; to make peaceful; to quiet down
平民憤 (píng mínfèn) - to assuage popular indignation
你先平平氣！ (Nǐ xiān píng píng qì!) - Just calm down a bit first!
7. to pacify
平叛 (píngpàn) - to suppress a rebellion
8. ordinary; common; mediocre; average
平日 (píngrì) - normal days
平凡 (píngfán) - ordinary
平民 (píngmín) - civilian
Synonyms: 常, 庸
Antonyms: 奇, 特
9. (Chinese phonetics) level tone (one of the four tones in Middle Chinese)
平上shǎng去入 (píngshǎngqùrù) - the four tones of Middle Chinese: level, rising, departing and checked
陽平 (yángpíng) - light level tone
10. (Cantonese, Hakka) cheap; inexpensive
平peng4 機票piu3 - cheap air tickets
平peng4 啲得唔得呀？ - Can it be cheaper?
不如平peng4 平peng4-2 地dei6-2 賣畀我啦。 - What about selling it to me at a lower price?
Antonyms: 貴, tr=-
11. (Min Nan, Hakka) the same
伊佮我平懸。 (i1 gah4 ua2 bên5 guin5.) - He is as tall as me., MN-T
12. (historical) Short for 北平
^平 ^津戰役 (Píng Jīn zhànyì) - Pingjin campaign
13. Short for 平方米, square metre Used with numbers without classifiers.
14. , number 95 of the Baijiaxing
15. Alternative form of 辨
16. (obsolete) to control prices
17. Variant of 抨
原
1. meadow; field; plain; prairie; tundra; wilderness
2. source; origin; beginning
3. Original form of 源 (fountainhead; source)
4. basic; fundamental
5. original; primary
6. originally; at the beginning
7. to originate; to arise
8. to trace the source; to probe into
9. (literary, or in compounds) to forgive; to pardon
原諒 - to forgive
原宥 - to forgive
原goân情chêng - to forgive, MN
Yuan

Translations for 原 and their definitions

平
1. level; even; flat
平放 (píng fàng) - to put horizontally
平原 (píngyuán) - plain
馬路很平。 (Mǎlù hěn píng.) - The road is very flat.
2. equal; fair
平分 (píngfēn) - to divide evenly
持平 (chípíng) - impartial
Synonyms: 均
3. equal
平輩 (píngbèi) - same generation
平起平坐 (píngqǐpíngzuò) - to be on an equal footing
平了世界紀錄 (píng le shìjiè jìlù) - equalled a world record
雙方打成五平。 (Shuāngfāng dǎ chéng wǔ píng.) - They reached 5-5.
4. to level; to make level
5. calm; peaceful
太平 (tàipíng) - peaceful and tranquil
風平浪靜 (fēngpínglàngjìng) - to have no waves
心平氣和 (xīnpíngqìhé) - even-tempered and good-humoured
Synonyms: 穩, 靜
6. to calm down; to make peaceful; to quiet down
平民憤 (píng mínfèn) - to assuage popular indignation
你先平平氣！ (Nǐ xiān píng píng qì!) - Just calm down a bit first!
7. to pacify
平叛 (píngpàn) - to suppress a rebellion
8. ordinary; common; mediocre; average
平日 (píngrì) - normal days
平凡 (píngfán) - ordinary
平民 (píngmín) - civilian
Synonyms: 常, 庸
Antonyms: 奇, 特
9. (Chinese phonetics) level tone (one of the four tones in Middle Chinese)
平上shǎng去入 (píngshǎngqùrù) - the four tones of Middle Chinese: level, rising, departing and checked
陽平 (yángpíng) - light level tone
10. (Cantonese, Hakka) cheap; inexpensive
平peng4 機票piu3 - cheap air tickets
平peng4 啲得唔得呀？ - Can it be cheaper?
不如平peng4 平peng4-2 地dei6-2 賣畀我啦。 - What about selling it to me at a lower price?
Antonyms: 貴, tr=-
11. (Min Nan, Hakka) the same
伊佮我平懸。 (i1 gah4 ua2 bên5 guin5.) - He is as tall as me., MN-T
12. (historical) Short for 北平
^平 ^津戰役 (Píng Jīn zhànyì) - Pingjin campaign
13. Short for 平方米, square metre Used with numbers without classifiers.
14. , number 95 of the Baijiaxing
15. Alternative form of 辨
16. (obsolete) to control prices
17. Variant of 抨

簡單
1. adj. simple; uncomplicated; easy
簡單碳水.化合物 - simple carbohydrate
簡單易用 - simple and easy-to-use
這道題太簡單了。 - This question is so easy.
2. adj. (chiefly in the negative) commonplace; ordinary
3. adj. sloppy; careless; skimpy; negligent; casual; oversimplified