Raling
Raling, or railing, meaning painful. This means that Boo Radley had a painful cough, probably developed after spending most of his life inside. This cough also symbolises the pain that Boo Radley has, from being mistreated, shunned and misunderstood. The cough is also used here to represent Boo Radley's unease at being outside his house, and interacting with other people.