Well, is it?
Or is it an adjective?
Was it the name that God Almighty lent to the way of life He Ordained for man?
Or is it an Arabic word descriptive of the way of life into which man was to strive to attain, that is, the attainment to a state of peace through surrender to His Will?
Is it an Arabic word that is just as susceptible to translation, like any other Arabic word?
Take the last part of Surah 5 verse 3.
This day have I perfected for you your religion ( diina ) and completed My favor on you and chosen for you Islam as a religion ( diina ); but whoever is compelled by hunger, not inclining willfully to sin, then surely Allah is Forgiving, Merciful - as translated by Shakir.
Could ‘Islam’, like ‘diina’, in this verse, not be translated, too, into English?
For that matter, could ‘Allah’, too, not be translated?