名詞 delta:

1. a low triangular area where a river divides before entering a larger body of water
2. the 4th letter of the Greek alphabet

1. A section of the Meuse River flowing westward through the southern Netherlands to a joint delta with the Rhine River.
   馬斯河默茲河的一部分，向西流經(jīng)荷蘭南郊與萊茵河相匯而形成一片沖積三角洲
2. Sediment deposited by flowing water, as in a riverbed, flood plain, or delta.
   沖積層河床、洪水淹沒的平原或三角洲中的流水淤積所產(chǎn)生的沉積層
3. There are fertile fields in the Nile Delta.
   尼羅河三角洲土地肥沃。

del.ta

n.（名詞）
The fourth letter of the Greek alphabet.See table at alphabet
△，δ：希臘字母表中的第四個(gè)字母參見 alphabet
An object shaped like a triangle.
三角形物：形狀象三角形的物體

A usually triangular alluvial deposit at the mouth of a river.
三角洲：河口常見的三角形沉淀淤積地帶
A similar deposit at the mouth of a tidal inlet, caused by tidal currents.
三角洲：海灣入口處三角形沉淀區(qū)域，由潮汐形成
Mathematics A finite increment in a variable.
【數(shù)學(xué)】 變量增量：變量的有限增量

來源：
Middle English
中古英語
from Latin
源自 拉丁語
from Greek ; akin to Hebrew delet [door]
源自 希臘語 ；類似于 希伯來語 delet [門]
from Phoenician dalt
源自 腓尼基語 dalt

【引伸】
delta.ic
<注釋>A &S{D} sits at the mouth of many rivers.The Greeks, noticing the resemblance between the island formed by sediment at the mouth of a river such as the Nile and the triangular shape of their letter delta,gave the namedelta to such an island. English borrowed this sense from Greek,although the worddelta appeared first in English as the name of the letter, in a work written possibly around 200.The sense .alluvial deposit. is not recorded until 555,whendelta is used with reference to the Nile River delta.
位于許多河口的三角形區(qū)域。希臘人注意到河口（例如尼羅河）由泥沙沉淀生成的三角形島嶼與他們的字母&S{D}相似，因此用delta 來稱呼這些島嶼。 英語取義于希臘語，但是delta 最早出現(xiàn)在英語里是作為△這個(gè)字母的名稱， 它在書面的作品中出現(xiàn)大約是在200年左右。.淤積沉淀.這個(gè)含義直到555年才有記載，那時(shí)delta 被用于特指尼羅河口的三角洲