Synonyms of the word

infrequent

• adj. Not frequent; not happening frequently.

occasional

• adj. Occurring or appearing irregularly from time to time.
• adj. Not very often.
• adj. Created for a specific occasion.
• adj. Intended for use as the occasion requires.
• adj. Acting in the indicated role from time to time.

rare

• adj. (cooking, particularly meats) Cooked very lightly, so the meat is still red (in the case of steak or beef…
• adj. Very uncommon; scarce.
• adj. (of a gas) Thin; of low density.
• v. (US, intransitive) To rear, rise up, start backwards.
• v. (US, transitive) To rear, bring up, raise.
• adj. (obsolete) early.

sporadic

• adj. (archaic) (of diseases) occurring in isolated instances; not epidemic.
• adj. Rare and scattered in occurrence.
• adj. Exhibiting random behavior; patternless.