Answer:

operant

Answer	Crossword Clue
OPERANT	Working.
OPERANT	Performer.
OPERANT	Manager.

OPERANT	In running order.
OPERANT	Agent.
OPERANT	Producing an effect
OPERANT	Effective
OPERANT	At work
OPERANT	Having an effect
OPERANT	In effect

Crossword

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