Let us start with the three groups of clues encountered in the classical crossword  synonyms, superordinates, and definitions.
( ( Let ( us ( start ( with ( ( the ( three groups ) ) ( of ( clues ( encountered ( in ( ( ( ( ( ( the ( classical ( crossword synonyms ) ) ) , ) superordinates ) , ) and ) definitions ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (VP (VB Let) (S (NP (PRP us)) (VP (VB start) (PP (IN with) (NP (NP (DT the) (CD three) (NNS groups)) (PP (IN of) (NP (NP (NNS clues)) (VP (VBN encountered) (PP (IN in) (NP (NP (DT the) (JJ classical) (JJ crossword) (NNS synonyms)) (, ,) (NP (NNS superordinates)) (, ,) (CC and) (NP (NNS definitions)))))))))))) (. .)))
We will end with definitions and synonyms.  
( We ( ( will ( end ( with ( ( definitions and ) synonyms ) ) ) ) . ) )
(ROOT (S (NP (PRP We)) (VP (MD will) (VP (VB end) (PP (IN with) (NP (NNS definitions) (CC and) (NNS synonyms))))) (. .)))