形容詞 forgetful:

1. (of memory) deficient in retentiveness or range
   同義詞：unretentive, short
2. not mindful or attentive- G.B.Shaw
   同義詞：unmindful, mindless
3. failing to keep in mind
   同義詞：oblivious

1. She is forgetful of her object.
   她忘卻了自己的目標(biāo)。
2. Children are forgetful and must be told time and again how to behave.
   孩子們沒記性，必須反復(fù)告訴他們怎樣表現(xiàn)自己的舉止。
3. Grandfather is forgetful and often repeats himself when he tells a story.
   爺爺記憶不好，他講故事的時(shí)候老愛重復(fù)。

for.get.ful

adj.（形容詞）
Tending or likely to forget.
健忘的：傾向于或似乎忘記的
Marked by neglectful or heedless failure to remember:
不經(jīng)心的；疏忽的：以疏忽的或不經(jīng)心的無法記起為特征的：
例句：
forgetful of one`s responsibilities.
玩忽職守

Causing one to be unable to remember.
導(dǎo)致忘卻的

【引伸】
forget.fully
adv.（副詞）
forget.fulness
n.（名詞）
<參考詞匯><同義詞>forgetful,unmindful,obliviousThese adjectives refer to inability or failure to remember.
這些形容詞指不能或無法記起。
Forgetful usually implies a faulty memory or a tendency not to remember:
Forgetful 通常含有記憶力衰退或失去記憶的意思：
例句：
As I grow older I become increasingly forgetful. Less often the word is used as the equivalent ofunmindful, which applies principally to failure to keep in mind what should be remembered, as through deliberate oversight, heedlessness, or inattentiveness:
隨著年齡的增長，我變得越來越健忘了。 偶爾這些詞可用來代替unmindful， 該詞主要用于指有意的疏忽、心不在焉或漫不經(jīng)心等，而將應(yīng)該記住的事忘了：

例句：
She ought not to be forgetful of her duties.
她不該玩忽職守。

例句：
Each passenger rushed toward the exit, unmindful of the others.
每個(gè)乘客都不顧其他人涌向出口。

Oblivious refers to failure rather than inability to remember,as because one is preoccupied or because one has chosen to disregard something:
Oblivious 更側(cè)重于疏忽而不是失去記憶，如因?yàn)槟橙俗鍪乱恍囊灰饣蛴羞x擇地疏忽一些事情：
例句：
Fortunately for the author, he was soon oblivious of the vitriolic criticism. Sometimes the term implies lack of awareness:
幸運(yùn)的是，就作者而言，他很快就忘了這些辛辣的評論。 有時(shí)這個(gè)詞含有缺少意識的含義：

例句：
For a person who has known them so long you are strangely oblivious to their faults.
對于一個(gè)認(rèn)識他們很久的人來說，你異乎尋常地沒有意識到他們的缺點(diǎn)。