Words are historical archives of how people perceived the world, or their place in the world. They are products of evolution. Just as we can analyse an organism’s anatomy for clues of its evolutionary ancestor’s habitats and behaviour, a word’s etymology can give us clues of what was going on around people as the word developed, and thus what they needed to verbalise.
The first word in the series is ‘rival’ (n.).
It’s first known occurrence in English dates to 1577. It comes from the Latin ‘rivalis’, meaning either a ‘person using the same stream as another’ or a ‘person on the other side of the same stream’. ‘Rivus’ is Latin for stream or creek, hence English’s ‘rivulet’. ‘RIver’ is an obvious sibling. Also closely related is ‘riparian’, from Latin’s ‘ripa’, meaning ‘water’s edge’, and ‘riviera’. ‘Arrive’ originally meant ‘to come to land’ or ‘to touch the shore’. While ‘derive’ meant ‘to draw off a stream from its source’. And yet another cousin appears to be ‘riven’, as in ‘torn’. The imagery is obvious: a river is a tear in the fabric of a landscape.
Rival’s origin suggests the centrality of water to competition. Indeed, the association gets into narratives about water and conflict. If competition were originally involved, it is unclear whether the competition was over the water resource or merely divided by it. But it is also quite possible that the competitive connotation was not originally ascribed to the word. More research on my part is in order, or assistance from the audience?