(countable, informal, uncountable) Marble or a marble made of agate, or one that looks as if it were made of agate.
Mrs. Collins. Never seen so many children out. Snowmen in every yard this year.
Billy. Look at mine, Mr Willis. Got a baseball for a nose and my best aggies for eyes.
Mr. Willis. Yeah, marbles are fine—but in my day we used coal. 1950, The Martian Chronicles, Ray Bradbury
Most of the time it went fine; some of his classmates had so many marbles they could have opened up their own shop in smurfs, pirates, purple aggies and pink panthers. 1999, Abdelkader Benali, Susan Massotty, Wedding by the Sea, page 60:
Etymology tree
Middle French agriculturebor.
Proto-Indo-European *h₂eǵ-?
Proto-Indo-European *h₂éǵros
Proto-Italic *agros
Latin ager
Proto-Indo-European *kʷelh₁-
Proto-Indo-European *-eti
Proto-Indo-European *kʷélh₁eti
Proto-Italic *kʷelō
Latin colō
Proto-Indo-European *-tew-?
Proto-Indo-European *-r-eh₂?
Latin -tūra
Latin cultūra
Latin agricultūrabor.
Middle English agriculture
English agriculture
Proto-Indo-European *h₂el-
Proto-Indo-European *-is
Proto-Indo-European *h₂élisder.?
Proto-Italic *-ālis
Latin -ālisbor.
Old French -albor.
▲
Latin -ālis
Old French -elbor.
▲
Latin -ālisbor.
Middle English -al
English -al
English agricultural
English -ie
English aggie
From agricultural + -ie.
Meanings
(US, informal) An agricultural school, such as one of the state land-grant colleges.
(US, informal) A student or alumnus of such a school.
I got aggie like a motherfucker. 2006, Noire [pseudonym], Thug-A-Licious: An Urban Erotic Tale, New York, N.Y.: One World, Ballantine Books, →ISBN, page 191: