1
As they approached the confines of society the train was blended among a thousand others.
2
Some kind of writing. Doctor Bob always became vague and clumsy when he approached the confines of literature.
3
As they approached the confines of the farm they heard distant barking, and then the voices of human beings.
4
When the jest grew subtle she was less pleased; but, if it approached the confines of the indecorous, the danger was serious.