Definitions
1.nounA subordinate.
2.nounA commissioned officer having a rank below that of captain; a lieutenant or second lieutenant.
3.nounA subaltern proposition; a proposition implied by a universal proposition. For example, some crows are black is a subaltern of all crows are black.
4.noun(literary theory) A member of a group that is socially, politically and geographically outside of the hegemonic power structure of the colony and of the colonial homeland.
5.adjectiveOf a lower rank or position; inferior or secondary; especially ranking as a junior officer, below the rank of captain."a subaltern officer"
6.adjectiveAsserting only a part of what is asserted in a related proposition.