Spelling Bee: Root words?

I'm entering in my first spelling bee. Winners will go on to the Scripps National Bee. I'm trying to find the root words to some of the words, but I can't EXAMPLE: succinct. Root words? "early 15c., from M.Fr. succincte, from L. succinctus "prepared, ready, contracted, short," pp. of succingere "tuck up (clothes for action), gird from below," from sub "up from under" + cingere "to gird" (see cinch). Sense of "compressed" first recorded 1530s." I don't understand any of that. What is "pp."? I know L. is Latin.