Rockers and Trough

Rockers noun - Originally a British youth subculture that evolved out of the teddy boys in the 1960s; wore black leather jackets and jeans and boots; had greased hair and rode motorcycles and listened to rock'n'roll; were largely unskilled manual laborers.

Trough and rockers are semantically related. In some cases you can use "Trough" instead a noun "Rockers".

Trough noun - A long hollow cylinder for carrying a substance (as a liquid or gas).

Rockers and trough are semantically related. Sometimes you can replace term "Rockers" with "Trough", this nouns are similar.