فوق لیسانس مترجمی زبان انگلیسی

periodic, intermittent, occasional, sporadic, 

CORE MEANING: recurring over a period of time

periodic used to indicate that something occurs at intervals, suggesting a degree of regularity; intermittent used to indicate that something occurs at irregular intervals and emphasizing the absence of continuity or regularity; occasional used to indicate that something occurs infrequently and irregularly, often used to describe something fairly minor or unimportant; sporadic used to indicate that something occurs irregularly and unpredictably, often implying scattered instances