| time |
| intermittently(expression, adverb, time, rare, frequency) |
| periodically(expression, adverb, time, rare, frequency) |
| alternately(adverb, vacillating, uncertainly, intermittently, variably) |
| at irregular intervals(expression, idiom, adverb, uncertainly, variably) |
| at one time(expression, idiom, once, hitherto, sometime) |
| away back(expression, once, hitherto, sometime, erewhile) |
| back when(expression, once, hitherto, sometime, erewhile) |
| but once(expression, once, hitherto, sometime, erewhile) |
| in the old days(expression, idiom, once, hitherto, sometime) |
| in the olden days(expression, idiom, once, hitherto, sometime) |
| in times gone by(expression, idiom, once, hitherto, sometime) |
| in times past(expression, idiom, once, hitherto, sometime) |
| long ago(expression, once, hitherto, sometime, erewhile) |
| not often(expression, adverb, unusually, intermittently, occasionally) |
| now then(expression, adverb, uncertainly, intermittently, occasionally) |
| occasion |
| on one occasion(expression, idiom, once, hitherto, sometime) |
| once only(expression, once, hitherto, sometime, erewhile) |
| once upon a time(expression, idiom, once, hitherto, sometime) |