os·cil·la·tion 
/ˌɑ:səˈleɪʃən/ noun
plural os·cil·la·tions /ˌɑ:səˈleɪʃən/ noun 1 : the act of regularly moving from one position to another and back to the original position [noncount] ▪ the continued oscillation of the fan [count] ▪ the fan's oscillations 2 somewhat formal : a frequent change from one state, position, or amount to another [noncount] ▪ the continual oscillation [=(more commonly) fluctuation] of stock prices [count] ▪ price/temperature oscillations 3 somewhat formal : the act of changing from one belief, feeling, etc., to an opposite one — usually + between [noncount] ▪ There has been oscillation between optimism and pessimism among voters. [count] ▪ His friends were alarmed by his oscillations [=(less formally) swings] between hope and despair. 4 [count] technical : a single movement from one position or state to another
▪ Each oscillation of the pendulum represents one second.
▪ Each oscillation of the pendulum represents one second.
