She gave a nod to her friend across the room.

To make a slight downward movement of the head as a way of showing acknowledgment or greeting.
He nodded in agreement with the speaker.
They exchanged nods as they passed each other.
The teacher nodded to the students to start the lesson.
a friendly nod
a quick nod
nod of approval
acknowledge
greet
signal
She nodded when I asked if she was ready.

To move your head up and down to show agreement or understanding.
He nodded when I asked if he understood.
The teacher nodded to show she agreed with the idea.
They nodded in approval after hearing the proposal.
nod in agreement
nod your head
give a nod
agree
acknowledge
approve
He gave a nod to show he understood.

A quick movement of the head up and down, often to show agreement.
She gave a quick nod to the teacher.
He nodded in agreement with her suggestion.
The dog nodded its head when it saw the treat.
give a nod
nod in agreement
a quick nod
gesture
sign
acknowledgment