A coupling (or a coupler) is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, and is almost as important as the track gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together.
Myxedema (British English: Myxoedema) is a term used synonymously with severe hypothyroidism. It is also to describe a dermatological change that can occur in hypothyroidism, and some forms of hyperthyroidism. This article discusses the dermatological changes.
