"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" (from PIE root *al- "beyond").
sub
sub judice
sub rosa
sub voce
sub-acute
subaltern
sub-aqueous
sub-arctic
sub-atomic
sub-category
subclass
