Meaning of “diamond” - Learner’s Dictionary

diamond

noun uk us /ˈdaɪəmənd/
STONE [ C, U ]

B2 a very hard, transparent stone that is extremely valuable and is often used in jewellery:

a diamond ring
SHAPE [ C ]

B2 a shape with four straight sides of equal length that join to form two large angles and two small angles

BASEBALL [ C ]

the field where baseball is played

diamonds

playing cards with red, diamond shapes on them:

the queen of diamonds

(Definition of “diamond” from the Cambridge Learner’s Dictionary © Cambridge University Press)