Originally called nieces on a regular basis (3)
I believe the answer is:
nee
'originally called' is the definition.
(written before eg a maiden name)
'nieces on a regular basis' is the wordplay.
'on a regular basis' indicates alternate letters.
The alternate letters of 'nieces' are 'NEE'.
(Other definitions for nee that I've seen before include "Originally called" , "Born in France" , "Used to indicate the maiden name of a married woman" , "Name originally" , "Indicates the birth name of a married woman" .)