Intellectual means involving a person's ability to think and to understand ideas and information.
High levels of lead could damage the intellectual development of children.
高含铅量会损害儿童的智力发育。
If you describe someone as intellectual you mean that they spend a lot of time studying and thinking about complicated ideas.
They were very intellectual and witty.
他们非常聪明、机智。
intellectuals
An intellectual is someone who spends a lot of time studying and thinking about complicated ideas.
Teachers, artists and other intellectuals urged political parties to launch a united movement against the government.
教师、艺术家和其他知识分子敦促各政党发动一场反政府的联合运动。