He is a realist who values reality more than dreams.

He is a pure utilitarian, all his actions are based on the pursuit of profit.

He is known as an excellent realist.

He is known as an absolutist in politics.

He is a fervent communist.

My sister is a vegetarian and does not eat meat at all.

He claims to be a true democrat at heart.

He is a true optimist, always believing in a bright future.

She is looking for an ideal partner.

The law of ideal gas is a basic concept in physics.