The name "tacit" comes from the APL family as far as I know. It certainly fits with Iverson's style, as he was fond of seeking out just the right word to descri

The name "tacit" comes from the APL family as far as I know. It certainly fits with Iverson's style, as he was fond of seeking out just the right word to describe something regardless of obscurity ("ravel", "copula", etc.). I think the name would have come about after the development of function trains in 1988, and I found a paper "Tacit definition" about Iverson's J from 1991: https://dl.acm.org/doi/10.1145/114054.114077 https://dl.acm.org/doi/10.1145/114054.114077 (digitized at https://www.jsoftware.com/papers/TacitDefn.htm https://www.jsoftware.com/papers/TacitDefn.htm). Not knowing when "point-free" started to be applied to programming, I can't say which is first. I doubt J's developers were aware of "point-free" in any case.