• adj. 平的；简单的；朴素的；清晰的
• n. 平原；无格式；朴实无华的东西
• adv. 清楚地；平易地
• n. (Plain)人名；(英)普莱恩；(法)普兰

来自拉丁语planus,平的，来自PIE*pele,展开，放平，词源同plan,place.引申诸相关词义。

plain

plain: [13] Plain is etymologically the same word as plane in all its uses except the tree-name, and even that comes from the same ultimate source. This was Indo-European *plā- ‘flat’, which produced Greek platús ‘broad’ (source of English place, plaice, and platypus), Latin plānus ‘flat, clear’, and possibly English flat. The Latin word passed into English via Old French plain, but its original ‘flat’ senses have been hived off into the separately acquired plane, leaving only the metaphorically derived ‘clear’ senses. The Italian descendant of plānus has given English piano.
=> plane

plain (adj.)

c. 1300, "flat, smooth," from Old French plain "flat, smooth, even" (12c.), from Latin planus "flat, even, level" (see plane (n.1)). Sense of "evident" is from, c. 1300; that of "free from obstruction" is early 14c.; meaning "simple, sincere, ordinary" is recorded from late 14c., especially of dress, "unembellished, without decoration."

In reference to the dress and speech of Quakers, it is recorded from 1824; of Amish and Mennonites, from 1894 (in the Dutch regions of Pennsylvania Plain with the capital is shorthand adjective for "Amish and Old Order Mennonite"). Of appearance, as a euphemism for "ill-favored, ugly" it dates from 1749. Of envelopes from 1913. As an adverb from early 14c. Plain English is from c. 1500. Plain dealer "one who deals plainly or speaks candidly" is from 1570s, marked "Now rare" in OED 2nd edition. To be as plain as the nose on (one's) face is from 1690s.

plain (n.)

"level country," c. 1300 (in reference to Salisbury Plain), from Old French plain "open countryside," from Latin planum "level ground, plain," noun use of neuter of planus (adj.) "flat, even, level" (see plane (n.1)). Latin planum was used for "level ground" but much more common was campus.

1. It's plain that he adores his daughter, and the feeling is mutual.

明摆着他很喜欢自己的女儿，而且女儿也喜欢他。

来自柯林斯例句

2. Patterson pointed toward a plain cardboard box beneath a long wooden table.

帕特森指着长木桌下的一个普通的纸板箱。

来自柯林斯例句

3. Pregnancy wasn't all plain sailing and once again there were problems.

孕期并非一帆风顺，这不，又出现问题了。

来自柯林斯例句

4. It is stranded somewhat forlornly in the middle of the plain.

它有些孤零零地立在平原中央。

来自柯林斯例句

5. He wore a plain blue shirt, open at the collar.

他穿一件素净的蓝色衬衫，领口敞着。

来自柯林斯例句