no‧tice1 S1 W2 [intransitive,transitive not in progressive]
if you notice something or someone, you realize that they exist, especially because you can see, hear, or feel them:
He noticed a woman in a black dress sitting across from him.
I didn't notice any smoke.
Have you noticed any change in him?
I noticed that her hands were shaking.
He never seems to notice when people take advantage of him.
notice who/what/how etc
She hadn't noticed before quite how grey his hair was.
notice somebody/something doing something
Did you notice him leaving the party early?
to get attention, or to make someone get attention:
These clothes will get you noticed and enhance your image.
3 also somebody can't help but notice something
if someone can't help noticing something, they realize that it exists or is happening even though they are not deliberately trying to pay attention to it:
I couldn't help noticing the bruises on her arm.