Answer:

generation

Answer	Crossword Clue
GENERATION	About thirty years.
GENERATION	The Lost ... (post-W. W. I youths)
GENERATION	Kind of gap

GENERATION	Allotment of heredity units?
GENERATION	Followers of a boom?

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.