词根：-vent-

【词根含义】：来;风

【词根来源】：“来”的意义来源于拉丁语动词venio, venire, veni, ventus(来);“风”的意义来源于拉丁语名词ventus, venti, n(风)。

【同源单词】：advent, adventitious, adventure, adventurer, adventurous

前缀：ad-

【词根含义】：来,临近;朝,向,趋向;加强意义

【词根来源】：来源于拉丁语前缀ad-。

【同源单词】：adapt, adaptable, adaptation, adaptive, addict

词根词缀：ad-

【来源及含义】Latin: prefix; to, toward, a direction toward, addition to, near, at; and changes to: ac-, af-, ag-, al-, an-, ap-, aq-, ar-, as-, at- when ad- is combined with certain words that begin with the letters c, f, g, l, n, p, q, r, s, and t

【相关描述】The form ad- appears in this form before a vowel and before the consonants d, h, j, m, and v. It is simplified to a- before sc, sp and st.

Before c, f, g, l, n, p, q, r, s, and t; ad- is changed to ac-, af-, ag-, al-, an-, ap-, aq-, ar-, as-, and at-.

In other words, the d of ad usually changes into the same letter as the first letter of the following root or word when it is a consonant: ad-fix becomes affix, and ad-sign becomes assign; therefore, making a double consonant.

Another example includes: attract as with ad-tract (drawn towards); so it has a double t. On the other hand when ad- precedes a vowel, as with adapt, it is simply ad-apt, with one d. For the same reason, there is only one d in adore and adumbrate, because ad- has combined with orare and umbra each of which starts with a vowel.

So, remember: since these Latin words begin with vowels and not consonants, the d of ad does not double as shown in the previous examples.

【同源单词】a capite ad calcem, Ab ovo usque ad mala, Ab uno ad omnes, Abiit ad majores, abjure, accede

词根词缀：-itious

【来源及含义】Latin: a suffix; tending to, characterized by

【同源单词】adventitious, expeditious, fictitious

词根词缀：-ous, -ious, -eous

【来源及含义】Latin: full of or having the qualities of; in chemistry, a suffix denoting that the element indicated by the name bearing it, has a valence lower than that denoted by the termination -ic; as, nitrous, sulphurous, etc., as contrasted with nitric, sulphuric, etc.

【相关描述】Only a small number of the hundreds of examples are presented because there are just too many to include at this time.

【同源单词】abdominous, abiogenous, ablepharous, abstemious, acanthaceous, acanthocephalous

词根词缀：ven-, vent-, veni-, ventu-

【来源及含义】Latin: come, coming

【同源单词】Ab inconvenienti, advene, advenement, advenient, Advent, advent