These two words have nothing in common except their sound. Phase is used mainly as a noun meaning ‘a stage in a process,’ although it has many more uses, discussed below. Faze is used only as a verb, meaning ‘to disturb someone and make them feel uncertain or afraid.’
Phase has a variety of meanings related to ‘a stage in a process’:
Teenagers often go through a rebellious phase before growing up.
During the first phase of the operation, the patient is put to sleep.
Liquids, solids, and gasses are phases of matter as we know it.
In the last sentence, these are called phases, because matter changes from one form to the other when it is heated or cooled – i.e. they are stages in a process.
Phase also has a related technical meaning, common enough to be worth knowing:
What phase was the moon in last night; was it full?
Scientists have discovered that oscillating systems tend to get in phase with each other.
Phase has the same meaning in the two previous sentences—a stage in a cyclical or circular process.
The moon’s various stages (full, waxing, waning, gibbous, etc.) are called phases. And every oscillating or cycling system, every wave, and every sub-atomic particle, is in some phase at any given time. Two clocks which are synchronized (show the same time) are in phase; if not, they are out of phase.
Finally, phase is also used as a verb, in phase in and phase out, meaning “to change (add or take away) in stages” (instead of all at one time):
We need to gradually phase out coal as an energy source.
The government plans to phase in the new policies one stage at a time.
Phase has other rare uses, all related to the stages of a process or cycle.
Faze, on the other hand, is always a verb, and always means “to disturb someone, making them uncertain or afraid”:
Nothing fazes him; he’s always calm and cheerful.
Faze is a young word, used in casual conversation more than in formal contexts.
More Examples of "Faze" in a Sentence
- The rain didn't faze me because I had an umbrella.
- John's anger didn't faze me.
- I'm not fazed by criticism; it's useful feedback.
- She was not fazed by his rude remarks.
- The noise of children playing in the background did not faze her.
- I was completely unfazed by the news.
More Examples of "Phase" in a Sentence
- We learned about the phases of the moon.
- I'm going through another phase in my life.
- The company is going through a growth phase.
- There are many phases of life that you have yet to experience.
- Phase 2 is currently underway with a timeline for completion by next month.
- The proposal will be completed in three phases over the next 12 months.
Tips for Remembering the Difference
Remember that faze is typically used as a verb, whereas phase is commonly used as both a noun and a verb. Faze is indeed a real word but is considered informal or even slang by some; it's almost always used as a verb.
Here's a useful sentence that illustrates the difference:
I am ready to start a new phase in my life, and this time I won't let setbacks faze me.