Definition of: marginal

(mär′jə·nəl) adjective
1. Pertaining to or constituting a margin.
2. Written, printed, or placed on the margin.
3. Psychol. Relating to the fringe of consciousness.
4. Econ. Operating or furnishing goods at a rate barely meeting the costs of production.
5. Of a nature that barely qualifies as useful, productive, or necessary.
—mar′gi·nal·ly adverb