Is there such a thing as a safe expression of love?
He did not know the meaning of that idiomatic expression in Spanish.
She wore a puzzled expression as she entered the room.
against the law, or expression of aggression
Logarithm is a mathematical expression and is very important. This is the sentence which contains the word logarithm.
The expression on her face was priceless. He used an antiquated expression to describe the book. The gift was an expression of love for his daughter.
A word or a phrase that shows the meaning to a sentence
his consternation was evident by the pained expression on his face.
He had a quizzical expression on his face.
Sentence, expression, diction, slogan
The World in a Sentence would be - A Vast expression of nature mistreated.
A dour expression may conceal a warm heart.
conjunction
He had a dour expression on his face as he listened to the bad news.
"thoughtful not joking" is not a sentence and it does not contain the word "serious". Serious is an adjective, a word that describes a noun. Example: Justin has a serious expression on his face. The adjective "serious" describes the noun "expression".