form [ME] Form goes back to Latin forma ‘a mould or form’, and is an element in many English words such as conform [ME] make like something else; deform [LME] ‘mis-shape’; and reform [ME] ‘put back into shape’. Formal [LME] originally meant ‘in proper form’, and developed the sense ‘prim, stiff’ in the early 16th century. Format [M19th] came via French and German from Latin formatus (liber) ‘shaped (book)’. Formula [E17th] was in Latin a ‘little form’ and was at first a fixed form of words used in ceremonies. Use in chemistry is from the mid 19th century.