Able to be measured. / Of significant importance.

That which can be measured; a metric.

(London) The London Underground Metropolitan Line / (London, historical) The Metropolitan Railway / (London, law enforcement, usually with "the") The Metropolitan Police Service of London (MPS)

(London, informal) A Metropolitan Line train / (baseball) A player for the New York Mets

Having meaning, significant.

Lacking meaning. / Insignificant; not worthy of importance.

The hobby of using a metal detector to hunt for buried coins or archaeological artifacts.

Any of various medical methods and practices used in place of, or as well as, conventional medicine.

A hand-held device that uses electromagnetic induction to detect buried metal.

(idiomatic, archaic, rare) A person who has a cough which causes them to sound as if they are barking.