Answer:

class

Answer	Crossword Clue
CLASS	Group of students
CLASS	Polish
CLASS	Social stratum

CLASS	Grace
CLASS	Business or economy
CLASS	Group above an order
CLASS	Elegance and style
CLASS	Elegance
CLASS	Reunion group
CLASS	Kind of clown or act
CLASS	Learning level

CLASS	Collection of students
CLASS	Social rank
CLASS	... participation (grading criterion)
CLASS	Professor's audience
CLASS	Top-notch
CLASS	Schoolroom group
CLASS	Student group
CLASS	Dignified quality

CLASS	School group
CLASS	Coach in the air?
CLASS	.. clown
CLASS	Word with act or action
CLASS	Teacher's group
CLASS	Recess preceder
CLASS	Taxonomic group
CLASS	What a truant skips

CLASS	Word after tourist or middle
CLASS	Sophomores or seniors
CLASS	Teacher's charges
CLASS	Freshman or sophomore
CLASS	Rank below phylum
CLASS	History or English
CLASS	Seniors, e.g.
CLASS	Type of warfare

CLASS	Kind of clown
CLASS	English 101, for one
CLASS	Teacher's venue
CLASS	Pupil's milieu
CLASS	Business or coach