Sentence:  Present at the Battle of Jutland, he had been recalled for the duration of this war and, being in the area, he had come to see how his little lad was faring in the sky. I was given permission to fall out and join him, gladly setting aside my <WSD>groundling's </WSD> bayonet. 
Meaning of the word marked with <WSD> tags:  A soldier who fights on the ground or serves as ground crew, as opposed to a seaman, pilot, etc.