Tenuki
From HexWiki
Tenuki means to play elsewhere, i.e., in a different area of the board than the opponent's last move. The term "tenuki" is borrowed from the game of Go.
The more stones are put in an area, the less attractive the area becomes. Hence, there always comes a point when it's better to play in a different area than to keep fighting for the same one.
Tenuki is highly underappreciated by less advanced players who tend to play locally for too long.