These two words have quite unrelated meanings.
Defuse, as a verb, means “cause something dangerous to become not dangerous”; originally, it referred specifically to bombs, which have fuses—the strings that catch on fire to light a primitive bomb (at least in cartoons). However, nowadays, defuse can be used for anything dangerous:
We hope that a good meal will defuse his anger.
Good police officers will defuse a situation before using their weapons.
Diffuse, as a verb, means “to spread out or through an area or substance”—like watercolor paints spreading through paper, or ink spreading through water:
After the concert, the crowd quietly diffused through the downtown area to various clubs.
Dangerous ideas can diffuse through a population very quickly over the internet.
Diffuse can also appear as an adjective, meaning “scattered, disorganized, sporadic, or spread apart”:
After the concert, diffuse fights broke out, between sports fans across the city.
This word is often used to describe badly organized language:
His arguments were too diffuse to follow clearly.
How to Use "Defuse" in a Sentence
Here are more examples of how to use "defuse" in a sentence:
- The bomb was defused by the police before anyone was hurt.
- To defuse the situation, John and I agreed to disagree.
- When emotions are running high, it's easy for a small argument to escalate into a full-blown fight, so it's important to know how to defuse a situation before it gets out of hand.
- Sometimes, the best way to defuse a tense situation is to laugh it off.
- Julio tried to defuse the tension in the room by cracking a joke.
- The negotiators were able to defuse the hostage situation without anyone getting hurt.
How to Use "Diffuse" in a Sentence
Here are more examples of how to use "diffuse" in a sentence:
- The light was too bright and needed to be diffused so that we could see.
- The light from the lamps diffused in every direction and lit up the floor.
- Because of the diffusive effects of the sun, the moon, and the stars, there are hours of daylight and darkness during the daytime.
- The diffusion of light can be used to create a sense of calm and serenity in a room or space.
- In interior design, diffuse light can be used to brighten up a dark corner or to make a space feel more open and airy.
- The aroma of coffee diffused throughout the café, making everyone feel at home.
- The smoke from the fire diffused throughout the house, making it difficult to breathe.
- Sometimes all it takes is using the right words or taking a step back to diffuse an argument.