mid-14c., "to form a mental image of," from O.Fr. imaginer, from L. imaginari "to form a mental picture to oneself, imagine" (also, in L.L. imaginare "to form an image of, represent"), from imago (see image). Sense of "suppose" is first recorded late 14c. Imaginary "not real" is from late 14c. (ymaginaire). First record of imagination "faculty of the mind which forms and manipulates images" is from mid-14c. (ymaginacion). Imaginative first attested late 14c. (ymaginatyf).