Hidari means “left”, giccho is a (redundant) slang word for “left-handed.” The usual phrase is hidari te, where te means hand. Giccho carries negative connotations, which I suppose is within the context of a largely right-handed society.
When I was a kid, I didn’t realize the connotations. My parents always described me as hidari giccho, so when I had referred to myself by that phrase to a Japanese teacher some years later, she was taken aback, and had to explain to me that it was a derogatory term.
I am the only left-handed person in my family, and in my extended family as well. I supposedly have two cousins who had initially shown left-handed tendencies, but they were taught to use their right hand when writing, so now they are right-handed.
I’m glad that my parents didn’t try to force me to be right-handed, but it did create problems learning to write in Japanese, where the lines must be done in prescribed directions and order; and when I was learning any kind of craft like knitting or origami.