related to daily cycles or activities

active during the day

दिन के दौरान सक्रिय

English Usage: Many mammals are diurnal, sleeping at night and hunting during the day.

Hindi Usage: बहुत से स्तनधारी दिन में सक्रिय होते हैं।

an irregular rising and falling in number or amount

variation or change

परिवर्तन या बदलाव

English Usage: There was a fluctuation in temperature throughout the week.

Hindi Usage: सप्ताह भर में तापमान में परिवर्तन हुआ।