gap
/ˈgap/
noun
a break in a barrier (such as a wall, hedge, or line of military defense)
an assailable position
a mountain pass
verb
to make an opening in
to adjust the space between the electrodes of (a spark plug)
to fall or stand open
noun
an area of contact between adjacent cells characterized by modification of the plasma membranes for intercellular communication or transfer of low molecular-weight substances