名詞 definition:

1. a concise explanation of the meaning of a word or phrase or symbol
2. clarity of outline

1. The book attempts a definition of his role in world politics.
   該書要闡明的是他在世界政局中的作用。
2. To give a definition of a word is more difficult than to give an illustration of its use.
   給一個詞下定義要比舉例說明它的用法困難。
3. The photo lacks definition.
   這張照片不夠清晰。

def.i.ni.tion

n.Abbr. def.（名詞）縮寫 def.

A statement conveying fundamental character.
定義：表達(dá)基本特征的說明
A statement of the meaning of a word, phrase, or term, as in a dictionary entry.
釋義：對單詞、短語或術(shù)語的意義的說明，如字典的詞條中的解釋
The act or process of stating a precise meaning or significance; formulation of a meaning.
解釋：對意思或意義的精確表達(dá)或表達(dá)的過程；對意思確切的闡述

The act of making clear and distinct:
清晰：使…清楚明晰的行為：
例句：
a definition of one`s intentions.
意圖的清楚表達(dá)

The state of being closely outlined or determined:
輪廓清晰：指輪廓非常分明的狀態(tài)：
例句：
.With the drizzle, the trees in the little clearing had lost definition.(Anthony Hyde)
.綿綿細(xì)雨中，那片小空地上的樹木都分辨不出輪廓了.(安東尼·海德)

A determination of outline, extent, or limits:
規(guī)定：對要點、范圍或界限的確定：
例句：
the definition of a President`s authority.
對總統(tǒng)權(quán)力的界定

The clarity of detail in an optically produced image, such as a photograph, effected by a combination of resolution and contrast.
清晰，分解：在視覺產(chǎn)生的意象中，枝節(jié)部分清楚明晰是由分解和對比相結(jié)合造成的，如照片
The degree of clarity with which a televised image or broadcast signal is received.
清晰度，分解力：接收到電視傳播圖象或廣播信號的清晰程度

來源：
Middle English diffinicioun
中古英語 diffinicioun
from Old French definition
源自 古法語 definition
from Latin dôfonotiô- dôfonotiôn-
源自 拉丁語 dôfonotiô- dôfonotiôn-
from dôfonotus [past participle of] dôfonore [to define] * see define
源自 dôfonotus [] dôfonore的過去分詞 [限定] *參見 define

【引伸】
def.ini.tional
adj.（形容詞）