Above: Using oxy-fuel cutting equipment to cut through a steel bar. Credit: Skeeze.
Latdict (latin-dictionary.net) defines punctum as a latin word meaning: tiny amount, dot/spot, pin prick, point, small hole, puncture, sting. And this cluster of interrelated definitions is very close to those in Barthes's Latin dictionary: "This second element which will disturb the studium [the general topic/subject matter of a photo-image] I shall therefore call punctum; for punctum is also: sting, speck, cut, little hole--and also a cast of the dice. A photograph's punctum is that accident [incidental detail] which pricks me--but also bruises me, is poignant to me."
As a photo-theory teacher teaching Barthes's theory of photography, I have found that undergraduate students generally find the term punctum too remote and too Latinate, too pompous.
And so I tend to seek substitute terms. One which seems to work well is simply "wound." Cut, little hole, puncture, pin prick: these are all types of injury, especially bodily injury. When I give this substitute term "wound" I always give in the context of the famous Jalal ad-Din Muhammad Rumi epigram: "The wound is the place where the light enters you.''
Another replacement term for the annoying punctum is frisson (ODE: "a sudden strong feeling of excitement or fear; a thrill: a frisson of excitement"). Frisson simply means shiver in French (Larousse.fr: "Tremblement involontaire, plus ou moins généralisé, des muscles"). I usually contextualize frisson as a shiver that gives you goose-bumps; a shudder.
(16 March 2018)