As nouns the difference between metra and metro
is that metra is the uterus while metro is an underground railway.
As an adjective metro is
metropolitan.
metra
English
Noun
(metrae)
(medicine) The uterus.
metro
English
Etymology 1
(etyl) .
Noun
(
en noun)
An underground railway.
A train that runs on such an underground railway.
An urban rapid transit light railway
A train that runs on such a railway.
Synonyms
* (underground railway) el/El (US), subway (US), Tube (the London underground), underground (UK), underground railway (UK)
Etymology 2
Noun
(
en noun)
A metropolitan area.