The term 'HEAL, AS BONE' can be solved by two four-letter crossword solutions: KNIT and MEND. The term 'heal, as bone' is a metaphor for repairing something that has been broken or damaged. To 'KNIT' something is to join together two or more pieces of material, such as yarn, thread, or fabric. To 'MEND' something is to repair it, usually with needle and thread. Both of these words can be used to describe the process of healing a broken bone, which requires the bone to be joined back together and repaired.