Hindu (= geoculturally Indian)
The word Hindu is more likely a loan word borrowed from outsiders like Persians who referred to us in one broad sweeping stroke as Hindus, those who belonged to a particular vast sub-continental landmass exhibiting any incredibly variegated social culture.
Hindu is considered a noun today so its essence as an adjective is called Hindutva. But Hindu is so complex a term that to reduce it to a noun is a travesty. Far better that we use Hindu as an Adjective that characterizes all those humans and human activities that are in that sub-continental landmass today shrunk down to India the nation-state. Anyway, let's use Hindu as a noun also.
Hindus are so diverse in their spiritual practices that the culture is the epitome of so-called Secularism, but here too by comparing Hinduism with Secularism would be yet another travesty. This is because the need for Secularism arose when the Church became so powerful over the State, that the State decided to push out the use of this soft power tool for global expansion as a velvet glove to cloak its hard power. Internal to the USA, the Church is very much in bed with the political policy making apparatus, which should make us think why is importing Secularism such a good idea when it is not being used in its home base? Think, think hard on this! When Abrahamic religions encounter foreign religions, or cultural practices, at best they can offer "Religious Tolerance" - such a weak standard of acceptance! It's like you come to my dinner table and tolerate my presence. The gall.
Hindus cultivate mutual respect for other spiritual practices because it is rooted in the thought that the Universe is an all pervasive Conscious Being, and why would the finger, for example, even want to contemplate poking its own eye? Mutual respect is a far superior concept to mere tolerance. Seeing divine consciousness everywhere also forces us to respect other beings as divine and no wonder we deify cows, rivers, mountains, trees, gurus, because they are manifestations of the universal Conscious Being. And hence Dharma, as a sustainable way of life.
Hindus, traditionally by design, separate so-called religious power (actually yogic & vedic knowledge), from that of state administration, wealth creation, and the trades including farming. Now that model has been completely lost thanks to British colonial interventions in Indic education where we were reduced to intellectual coolies and serfs. Each of these four sectors were allocated to Brahmins, Kshatriyas, Vaishyas and Shudras and although those born into such families had natural advantage to continue in that vein, the traditional egalitarian educational model afforded anyone to move across these sectors. With the advent of Racist British Colonial educational model we were fossilized into rigid Castes with no mobility thus completely strangulating the social architecture, and furthermore suffered from the decimation of the native school systems. Read Dharampal "Beautiful Tree". Caste is an imported Portuguese word and an imported British Colonial construct that has resulted in destructive Racial divisive policies that have been the direct cause of genocide, not just in India but anywhere the Racist Colonial monster has reared its ugly head, world over. Hindus have always stressed individual progress, and individual merit and need must govern future change, not group identity based politics at the detriment to the grand narrative of a unified India, otherwise called Akhanda Bharath.