Green’s Dictionary of Slang

eccy n.

also ec
[abbr.]

1. (US campus) economics.

1924
192419251926192719281929193019311932
1933
[UK]P. Marks Plastic Age 232: I’ve got a quiz in eccy to-morrow, and I’ve got to bone up on it some time to-night.
[US]G. Milburn No More Trumpets 89: If I flunk Ec I flunk out of school.

2. see ecky n. (1)