"junior military officer," 1680s, earlier more generally, "person of inferior rank" (c. 1600), noun use of adjective subaltern "having an inferior position, subordinate" (1580s), from Middle French subalterne, from Late Latin subalternus, from Latin sub "under" (see sub-) + alternus "every other (one), one after the other" (see alternate (adj.)).
中文解释
1. sub- "under" + altern-.2. => person of inferior rank.3. => 也就是在下面处于可替换位置的职位或职衔。