The term 'changes course suddenly' can be described by the crossword solutions SWERVES (7 letters), veers (5 letters), zag (3 letters), VEER (4 letters), ZIGS (4 letters), turns (5 letters), and tacks (5 letters). Swerving is a sudden change of direction, veering is a sharp turn, zagging is a sudden change of direction in a zigzag pattern, veering is a sharp turn, zigging is a sudden change of direction in a zigzag pattern, turning is a change of direction, and tacking is a change of direction while sailing. All of these words describe a sudden change of direction, which is the definition of the term 'changes course suddenly'.