agate

Etymology 1

From Middle French agathe, from Latin achatēs, from Ancient Greek ἀχάτης (akhátēs, “agate”).

noun

1. (countable, uncountable, mineralogy) A semitransparent, uncrystallized silicate mineral and semiprecious stone, presenting various tints in the same specimen, with colors delicately arranged and often curved in parallel alternating dark and light stripes or bands, or blended in clouds; various authorities call it a variety of chalcedony, a variety of quartz, or a combination of the two.
2. (uncountable, US printing, dated) The size of type between pearl and nonpareil, standardized as 5+¹⁄₂-point.
3. (countable, typography) One fourteenth of an inch.
4. (countable, obsolete) A diminutive person; so called in allusion to the small figures cut in agate for rings and seals.
5. (countable) A tool used by gold-wire drawers, bookbinders, etc.;—so called from the agate fixed in it for burnishing.
6. (countable) A marble made from agate.
7. (slang, usually in the plural) A testicle.

Etymology 2

a- (“on”) + gate (“way”)

adv

1. (obsolete) On the way; agoing.
   Go to it then hardily, and let us be agate. 1554, Interlude of Youth