1. the fifth in order or in a series.
2. ( sometimes l.c. ) (in some grading systems) a grade or mark, as in school or college, indicating the quality of a student's work is in need of improvement in order to be passing.
a. the third tone in the scale of C major or the fifth tone in the relative minor scale, A minor.
b. a string, key, or pipe tuned to this tone.
c. a written or printed note representing this tone.
d. (in the fixed system of solmization) the third tone of the scale of C major, called mi.
e. the tonality having E as the tonic note.
4. ( sometimes l.c. ) the medieval Roman numeral for 250. Cf. Roman numerals .
5. Physics , Elect.
a. electric field.
b. electric field strength.
6. Physics. energy.
7. Biochem. See glutamic acid .
8. Logic. See universal negative .
9. a proportional shoe width size narrower than EE and wider than D.