a.

1. 欠考慮的，粗心的，輕率的
2. 不顧及他人的，不為他人著想的
   It was very thoughtless of you to keep her waiting so long.

   你讓她等那麼久也太不體諒人了。

3. 沒有思想的；遲鈍的
4. 不考慮的[F][（+of）]
   be thoughtless of danger

   不考慮危險

adj.

1. not showing consideration for other people.
2. without consideration of the consequences.