Infrequent (adjective)

1. Not occurring often; rare.
2. Not happening or appearing frequently.

Origin:

Late 16th century (in the sense "not frequent"): from latin infrequent- "rare", from the prefix in- "not" + frequent- "frequent".

Examples:

1. Infrequent visits from family members can make the prisoner feel isolated.
2. The train service is infrequent, with only one train per hour.
3. Infrequent rainfalls made it hard for the crops to grow.
4. He had an infrequent habit of showing up unannounced.
5. The company's products are known to be of high quality, but infrequent updates can be frustrating.