The title says pretty much everything. Waveguide becomes wav-eguide Vertically becomes vertic-ally Important becomes import-ant Here are my modules:
\documentclass[11pt]{article}
\usepackage{eurosym}
\usepackage{siunitx}
\usepackage{graphicx}
\usepackage{cite}
\PassOptionsToPackage{obeyspaces}{url}
\usepackage{url}
\usepackage[raggedright]{titlesec}
\usepackage{gensymb}
\usepackage{polyglossia}
\setmainlanguage[variant=british]{english}
\newcommand{\sethyphenation}[2]{%
\AtBeginDocument{%
\begin{otherlanguage*}{#1}\hyphenation{#2}\end{otherlanguage*}%
}%
}
\sethyphenation{english}{wave-guide}
There's also a command I'm using to minimize this problem, as I thought it was just related to waveguide (maybe a word not in the dictionary), but as it appears to happen every time, I can't overwrite every single word like this.
(it was the same with babel and not polyglossia)
\sethyphenation{english}{wave-guide}and add\showhyphens{waveguide}then the system reports\TU/lmr/m/n/10.95 wave-guideshowing that the hyphenation is not, as you report, wav-eguide. If you do get that make an example, and show the log file. – David Carlisle Jul 16 '17 at 17:47wave-guide im-port-ant ver-tic-ally, which look right. – egreg Jul 16 '17 at 17:47eurosymwithfontspec, as you're currently doing. – cfr Jul 16 '17 at 22:51