Concept:
The words continual and continuous are often confused. Continuous means occurring without any break, whereas continual means occurring repeatedly with short interruptions.
Step 1: Understand the meaning of continual.
Continual refers to something that happens again and again over a period of time, but not necessarily without interruption.
Step 2: Differentiate between continual and continuous.
• Continuous rain = rain falling nonstop.
• Continual rain = rain occurring repeatedly with brief gaps.
Step 3: Match with the correct option.
Among the given choices, the meaning closest to continual is:
\[
\boxed{\text{Regular but interrupted}}
\]
This captures the idea of repeated occurrence with occasional breaks.