propadeutic		preliminary; introductory to some subject.
adumbrate		to give a shadow of, sketch; to foreshadow; to overshadow, conceal, or darken.
cinereous		ashen; resembling ashes; turned to ashes. also, |cineritious|.
decussate		to intersect at right angles; adj. crossed; (bot.) occurring in opposed pairs along the stem, each at right angles to the next. [< L /de~cussis/ the number ten]
enchiridion		a handbook or manual.
glacis		a slight slope.