периодически

1) General subject: at times, from time to time, now and then, on and off, on-and-off, once in a while, serially, occasionally, every so often, incidentally, intermittently

2) Engineering: at regular intervals, at regular times, regularly

3) Rare: termly

4) Mathematics: periodically

5) Law: on a periodic basis (англ. термин взят из публикации FATF: Risk-Based Approach. Guidance for the Insurance Sector. – October 2009)

6) Oil: in batches

7) Sakhalin energy glossary: on an intermittent basis

8) Makarov: serially (об издании и т.п.)

9) Aluminium industry: batchwise