If you dive into some water, you jump in head-first with your arms held straight above your head.

If you dive, you go under the surface of the sea or a lake, using special breathing equipment.

When birds and animals dive, they go quickly downwards, head-first, through the air or through water.

If an aeroplane dives, it flies or drops down quickly and suddenly.

If you dive in a particular direction or into a particular place, you jump or move there quickly.

If you dive into a bag or container, you put your hands into it quickly in order to get something out.

If shares, profits, or figures dive, their value falls suddenly and by a large amount.

If you describe a bar or club as a dive, you mean it is dirty and dark, and not very respectable.