Answer: atatime

AnswerCrossword Clue
ATATIME

Simultaneously

ATATIME

Unit by unit, in succession

ATATIME

Per instance

ATATIME
Together
ATATIME
Concurrently
ATATIME"... like this . . . "
ATATIMEOne ....
ATATIME"Stick to one thing ...."
ATATIMEOne ... (singly).
ATATIMEOne ...
ATATIMEOne ... (singly)
ATATIMEOne thing ...
ATATIME"One Day ...," TV sitcom
ATATIMEOrderly phrase that can follow one, two or three
ATATIMECompletion of "one day"
ATATIMEOne day ....
ATATIMEOne .... (singly)