agate definition by Webster's New World
- a hard semiprecious stone, a variety of chalcedony, with striped or clouded coloring
- any of various tools having agate parts, as a burnishing instrument with a tip of agate
- a little ball made of this stone or of glass, used in playing marbles
- a former small size of printing type, 5 points
Origin: Middle English agaten ; from Old French agate ; from Midieval Latin ; from Classical Latin achates ; from Classical Greek achatēs ; from uncertain or unknown; perhaps
agate definition by American Heritage Dictionary
- A fine-grained, fibrous variety of chalcedony with colored bands or irregular clouding.
- Games A playing marble made of agate or a glass imitation of it; an aggie.
- A tool with agate parts, such as a burnisher tipped with agate.
- Printing A type size, approximately 5 1/2 points.
Origin: Middle English achate, agaten, from Old French acate, agate, alteration (influenced by Greek agathē, good) of Latin achātēs, from Greek akhātēs.
agate - Science Definition