Inferior in rank or status.
1That ought to make him at least a junior-grade military genius.
2Harried noncoms and junior-grade officers buzzed everywhere, failing miserably to bring order to the chaos.
3He came to full attention and saluted the junior-grade lieutenant boat bay officer at the head of the side party.
4Unfortunately, she was a senior-grade captain and he was only a junior-grade lieutenant, which meant he had to answer her anyway.
5She was earmarked for a slot on Captain (Junior-Grade) Jacquelyn Harmon's staff, but Truman planned to borrow her quite often.