"sincere"

     [This is a fast-access FAQ excerpt.]
"Sincere" is sometimes said to derive from Roman quarrymen's
temporarily concealing imperfections in marble blocks by rubbing wax
on them.  On its AOL message board, Merriam-Webster Editorial
Department writes:  "The theory that 'sincere' ultimately derives
from Latin sine cera, meaning 'without wax', is a popular one;
unfortunately, there is no evidence to support it.  A far more
likely origin, in our view, is that the Latin word sincerus
derives from sem- ('one') and -cerus (akin to Latin crescere,
meaning 'to grow')."