What does "<someone> doesn't dream" mean?

Question

When I was reading a novel, I got confused by this sentence:

"When he is around, she doesn't dream."

Clearly it's not the literal meaning. Then what does it mean? Can you help me? My guess is "sleep well" or "carefree"

Answer 1

Without any further context, your example sentence

When he is around, she doesn't dream.

could have one of several different meanings

In order to dream during sleep one usually needs a quiet, undisturbed environment. Dreaming takes place during a phase called rapid eye movement, which occurs during deep sleep a few minutes after falling asleep, and only last for a relatively short period of time compared to the entire sleep duration.

Lack of dreaming can be a symptom that the person is on edge or worried since they will not allow themselves to fall into a deep sleep.

Your sentence could metaphorically mean she doesn't sleep well when he is around possibly due to his snoring or any one of a number of reasons.

To dream (about) is to think about or wish for or want something. Possibly your sentence is saying that when he is away, she dreams about him, but when he is around she has no need to do so.

She dreams about the day he returns
She dreams about chocolate cake every night

To dream can also mean to have ambition

She has no time for her own hopes and dreams when he is around

The question is

If he is not around, what would she be dreaming of?

Answer 2

The most obvious meaning is that she doesn't have aspirations or hopes when he is around.

Most people would consider this a literal use of the term dream. You probably mean that you know it doesn't mean dream in its most common sense of the brain activity that occurs during sleep.

It is quite apparently being used in the following sense:

v.
dreamed or dreamt (drĕmt), dream·ing, dreams v.intr.
...
3. To have a deep aspiration or hope: dreaming of a world at peace.

American Heritage Dictionary