This is thought disorder denoting a lack of connection between ideas.
Links between ideas may be illogical or the speech may wander between trains of thought.
The illogicality of the loosening of associations which is found in schizophrenia should be contrasted with the flight of ideas which characterises hypomania.
Loosening of associations is also called knight's move thinking. The move of the knight in chess is used as a metaphor for the unexpected, and illogical, connections between ideas.