# KOS_OP_ITEM_FAST_CLEAR - **Style**: FASTVAR (the key's slot). - **Stack**: `[..., obj] → [...]`. Delete obj[key] with the object on the stack and the key read from a fast slot. - **Compiler form:** The lowering of **ITEM_VAR_CLEAR**: every named operand has a fast slot. - **Implementation**: `koskari/lib/opcode/ITEM_FAST_CLEAR.c`