Capybaras in red bow tie are pictured in Nanning Garden Expo Park in Nanning, south China's Guangxi Zhuang Autonomous Region, ...

See? “By” originally means “bye” or byway. That’s why, in fact, some people still spell “by the by” as “by the bye”. By the way, “that is by the by or bye” in this sense (secondary) is an idiom that ...