The soldiers held this strongpoint, which was the most fortified position in the entire defense line.

strongpoint 是由形容词 strong（强壮的、坚固的）和名词 point（点、位置）组成的复合词，字面意思是"坚固的点"，引申为军事上的"要塞"或"据点"，指防御体系中特别加固的战略位置。