1) Alien drinking hole 2) Biggest key 3) Computer key 4) Elongated key 5) Key for parting words 6) Keyboard element 7) Keyboard feature 8) Keyboard part 9) Large keyboard key 10) Largest key on a keyboard 11) Long key 12) Low key 13) Most-used key 14) Parting-word facilitator 15) The longest key 
The space bar, spacebar, blank or space key, is a key on a typewriter or alphanumeric keyboard in the form of a horizontal bar in the lowermost row, significantly wider than other keys. Its main purpose is to conveniently enter a space, e.g., between words during typing. A typical space bar key is large enough so that a thumb from either hand can ...
• Alt. of key
[n] - the bar-shaped typewriter key that introduces spaces when used
noun the bar-shaped typewriter key that introduces spaces when used