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.