깐 is an attributive adjective form of 까다. 까다 can mean 1. to peel (the skin of fruit, etc). 2. to bare something by removing covering. 3. to hit/punch, For opening a can, we use 따다 (open by breaking the seal) more often, as in 깡통을 따다, 딴 깡통 (an opened can). 깐 is sometimes used, but it sounds a little slangy.

opened can. 깐 깡통 "깐" comes from 까다 for instance 열린 문 opened door. 닫힌 문 closed door. I hope this answer helps you.

깐 =open