Radicals ( Radical140) five strokes in Kanji;

dimensional, e.g.

string can travel in 1D; in common, environment as specified item 's hole board can define the string's direction; for basic understanding, e.g. laser;

directional, e.g.

;

logical, e.g.

arrow;
dart;

Chikai (i.e. given name); Tadashi (i.e. given name); Yatsugi (i.e. name);

numerological, e.g.

5;

structural, e.g.

regarding automotive cm (centimeter) scaled (arrival, departure), on board (on screen) arrow indicates and informs to commuters, operators, passengers, recorders, ... ;

variable velocity, depending upon (resistance (e.g. , , , , also see: Schematic Symbols), vacuum (e.g. null)) ... ;

Radicals;