marginal

adj

1. (not-comparable, usually)Of, relating to, or located at or near a margin or edge; also figurative usages of location and margin (edge).

   “The marginal area at the edge of the salt-marsh has its own plants.”

   “In recent years there has been an increase in violence against marginal groups.”

2. (not-comparable, usually)Of, relating to, or located at or near a margin or edge; also figurative usages of location and margin (edge).

   “There were more marginal notes than text.”

   “The early pages had marginal notes most of which were lost when rats nibbled away the manuscript edges.”

3. (not-comparable, usually)Of, relating to, or located at or near a margin or edge; also figurative usages of location and margin (edge).

   “Monmouthshire is a Welsh county marginal to England.”

4. (comparable, not-comparable, usually)Determined by a small margin; having a salient characteristic determined by a small margin.

   “His writing ability was marginal at best.”

   “Having reviewed the test, there are two students below the required standard and three more who are marginal.”

   “The pilots lacked experience flying in marginal weather conditions.”

5. (comparable, not-comparable, usually)Determined by a small margin; having a salient characteristic determined by a small margin.

   “He farmed his marginal land with difficulty.”

6. (Australia, New-Zealand, UK, comparable, not-comparable, usually)Determined by a small margin; having a salient characteristic determined by a small margin.

   “In Bristol West, Labour had a majority of only 1,000, so the seat is considered highly marginal this time around.”

   “In ‘battleground’ seats with the Conservatives, Liberal Democrat vote shares increased most in the most marginal seats.”

   “In Outer London, Harrow East is now a more marginal Labour hold than Harrow West.”

   “The pendulum lists the seats from least marginal to most marginal for the government on one side, and least marginal to most marginal for the opposition on the other side.”

   “He justified his comment by noting that the Labour Party had quickly committed to delivering a high-speed Leeds-Manchester line, and argued that pressure would grow on the Government because there were several marginal parliamentary seats around Leeds and Bradford.”

7. (not-comparable, usually)Pertaining to changes resulting from a unit increase in production or consumption of a good.
8. (not-comparable, usually)Marginalized.

   “The caseworker couldn't understand how I could have stretched out my last bit of money for so long. She seemed convinced that I was "hiding" income from her and interrogated me for I don't know how long. […] The system seems based on the assumption that people are "welfare cheats." If you don't speak English or are marginal in some other way, it's worse.”

noun

1. Something or somebody that is marginal.

   “[…] discusses those who belong to the discipline's dominant cults, the mainliners, and their relations with the marginals and mavericks.”

   ““We need a saint or some other symbol that will serve to anchor our faith into the foreseeable future. I have watched and waited for a saint but none showed up—not even a marginal saint. Mary is the first one, and we must not allow her ...”

2. A constituency won with a small margin.