An instrument for cutting; a section or segment.
[The first sense is from Greek -tomon, that cuts; the second is from Greek tomē, a cutting, both from temnein, to cut.]
The most common terms in the first sense are microtome (Greek mikros, small), an instrument for cutting extremely thin sections of material for examination under a microscope, and osteotome (Greek osteon, bone), a surgical instrument for cutting bone, typically resembling a chisel. Others exist in surgery, usually closely related to terms for a procedure that ends in -tomy or -ectomy, but they are relatively rare.
Terms in the second sense include three for sections of embryos that give rise to particular parts of the body: dermatome (Greek derma, skin), the part that develops into the connective tissue of the skin; myotome (Greek mus, mu-, muscle), into the skeletal musculature; sclerotome (Greek sklēros, hard), into bone or other skeletal tissue.
Epitome, a person or thing that is a perfect example of a particular quality or type, or a summary of a written work, derives from Greek epitemnein, to make an incision into, hence abridge.
Terms such as cyclostome and protostome contain the ending -stome instead.