Lockman and Trained worker

Lockman noun - A worker in charge of a lock (on a canal).

Trained worker and lockman are semantically related. In some cases you can use "Trained worker" instead a noun "Lockman".

Trained worker noun - A worker who has acquired special skills.

Lockman and trained worker are semantically related. Sometimes you can replace term "Lockman" with "Trained worker", this terms are similar.