They may occur infrequently or many times each minute.

I offered them the perfect name, a phenomenon which occurs far too infrequently.

Although church services in Manx were once fairly common, they occur infrequently now.

For many, visits occur infrequently and women do not often get to make telephone calls.

When fires occur infrequently, the forest has time to recover.

Would we necessarily know about them, since they occur so infrequently?

Other problems, like coughs, occur infrequently and may not be recognized as side effects.

Button B gives much larger rewards, but they occur infrequently.

The diagnosis of the illness can be quite difficult to make because the symptoms occur infrequently.

Part of what she has to say is reassuring: tornadoes occur infrequently.