1. a very small person.
|Henry IV Pt 2 I ii: I was never mann’d with an agate till now, but I will set you neither in gold nor silver, but in vile apparel, and send you back again to your master, for jewel.|
|Gloss. (1888) I 12: agate. used metaphorically for a very diminutive person, in allusion to the small figures cut in agate for rings.|
2. (US) a small penis.
|5000 Adult Sex Words and Phrases 12: agate (Sl.) n. a Penis of diminutive size.|
|Gay Sl. Dict. [Internet].|
3. see glassy (alley), the n.
SE in slang uses
(US black) to walk jauntily with one’s thumbs extended.
|Mister Jelly Roll (1952) 19: You should have seen one of those sports [...] walking along with a very mosey walk they had adopted from the river, called shooting the agate. When you shoot the agate, your hands is at your sides with your index finger stuck out and you kind of struts with it.|
|Record Changer June 10: He would walk with a cake walkish strut and ‘drive them chicks wild.’ This was called ‘shootin’ the agate.’.|