1.empty
2.hollow
3.as in 4 dimensional(bigger on the inside than on the outside)

an empty nothingness prone to collapse

a feeling of unhappiness because someone or something is missing/a feeling of unhappiness because someone or something is missing

The space between a steering wheel and the back of the drivers seat. Often occupied by a creature resembling a human.
Commonly seen in Taxis, trucks and other service vehicles.

a person with no ambition, goals, or meaning in life

An armour set in the online game by JaGex, it comes in a set of 4 items;
robe top
robe bottom
gloves
1 of 3 helmets
the 3 helmets each incorperate a different effect on the wearer. there is a ranger helmet, a melee helmet and a mage helmet (looks like a hood though -.-)

popular among rangers and melee warriors in PvP (player vs Player) and PvM (player vs Monster)

How you say "function" in the programming language of C#