1510s, from M.Fr. tome, from L. tomus "section of a book, tome," from Gk. tomos "volume, section of a book," originally "section, piece cut off," from temnein "to cut," from PIE *tom-/*tem- "to cut" (cf. second element in L. aestimare "to value, appraise," O.C.S. tina "to cleave, split," M.Ir. tamnaim "I cut off," Welsh tam "morsel"). Originally "a single volume of a multi-volume work;" sense of "a large book" is attested from 1570s.