If you were a resident of DC and worked at your college in MD, you would be a "non-resident" for MD tax purposes.
A "part-year" resident is someone who changes their permanent residence from one state to another during the year.
Maryland and DC are reciprocal states. This means if you are a resident of the District of Columbia and work in Maryland, you are not subject to Maryland taxes. If the college withheld MD taxes, you would have to file a "non-resident" MD tax return (Form 505 Maryland Nonresident Income Tax Return) to get a refund of MD taxes withheld. You can also file Form MW 507 with the college to stop further withholding.