CSS
.Lexical_Function:after {content: "\00a0" ; background-color: yellow ;} /* keep with next */
.Lexical_Function ~ .Lexical_Function:before { content: "; " ; background-color: red}

XHTML
<div class="Main"><a class="Lemma" id="hvo821">apaañchichdha</a><span class="Part_Of_Speech" lang="es">v. t.</span><span class="Definition" lang="es">hacer un canal</span><span class="Comment">para proteger la casa</span><span class="Example_Group"><span class="Example_Sentence" lang="stp">Xi apaañchichdha pim mɨjɨ dɨr jap dhi baaak na ba cham bha bakia gu suudai na bhai ba duukim.</span><span class="Example_Sentence" lang="es">Hagan un canal alrededor de la casa para que no entre el agua, pues ya va a empezar a llover.</span></span><span class="Variant_Group"><span class="Lexical_Function" lang="es">pret.</span><span class="Variant_Form">apaañchich</span><span class="Lexical_Function" lang="es">pres.</span><span class="Variant_Form">apaañchichun</span><span class="Lexical_Function" lang="es">Var.</span><span class="Variant_Form">apaañchixdha</span></span><span class="Cross_Reference_Type" lang="es">Sinón.</span><a class="Cross_Reference" href="#hvo635">akxidha</a></div>

I thought that the true space following the ; would allow the text to break
apaañchichun; Var. apaañchixdha
I think the engine should look ahead and see that
Var. apaañchixdha
will not fit so should break after the ;
There is nbsp following Var.

Jim Albright
Wycliffe Bible Translators

1. bad_break.png‎ 50.3 kB

If this is the way it must be, I might allow break at
Var.
apaañchixdha

but keep the nbsp for the first set of words.
[pret. apaañchich

CSS:
.Lexical_Function ~ .Lexical_Function:after {content: "\200B " ; background-color: green ;} /* allow break */
.Lexical_Function:after {content: "\00a0" ; background-color: yellow ;} /* keep with next */

But this too fails.

Jim Albright
Wycliffe Bible Translators

1. bad_break2.png‎ 48.7 kB