compendium (n.)

1580s, from Latin compendium "a shortening, saving," literally "that which is weighed together," from compendere "to weigh together," from com "with, together" (see com-) + pendere "to hang, cause to hang; weigh; pay" (from PIE root *(s)pen- "to draw, stretch, spin"). Borrowed earlier as compendi (mid-15c.).