In my text, I use (un)conditional (s. here if you wonder why), which causes the text to exceed the right margin - the text is no longer justified.
In minimal working example below, I used (UGLY) which will not cause a line break - in contrast to (PROBLEMATIC), what get's broken after (PROB.
So, in some sense it is the opposite of this question, where the aim was to prevent a line break via \mbox{(UGLY)tempor}. Here I could solve the problem by adding \linebreak in front of (UGLY)tempor, which is not a satisfying solution because some words before the \linebreak might change in future, leading to a misplaced linebreak. To wrap it up: How do I make LaTeX treating (UGLY)tempor as a normal word?
\documentclass[12pt]{article}
\begin{document}
Lorem ipsum dolor sit amet, consectetur adipisici elit, sed eiusmod (UGLY)tempor incidunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat.
\end{document}

(un)\nobreak\hspace{0pt}conditionaldid the job. Forlccodemy sense of LaTeX is too bad. If you want, you can try to explain it, but you don't need to. – Qaswed Apr 03 '18 at 16:59()as letters and, therefore, not to branch to the "I came across a non-letter" part of the algorithm. – Steven B. Segletes Apr 03 '18 at 17:07\lccodefor()means that(un)conditionalis now considered a 15-letter word to the hyphenation algorithm, and the presence of(and)do not prevent the algorithm from looking for patterns in what follows the). – Steven B. Segletes Apr 03 '18 at 17:15