Definition of "Diamond" :
noun: the baseball playing field
noun: the area of a baseball field that is enclosed by 3 bases and home plate
noun: a playing card in the minor suit that has one or more red rhombuses on it
"He led a small diamond."
noun: a transparent piece of diamond that has been cut and polished and is valued as a precious gem
noun: a parallelogram with four equal sides; an oblique-angled equilateral parallelogram
noun: very hard native crystalline carbon valued as a gem