This is the 10097th most frequent Catalan word.
oscil
"Oscil" is not a standard Catalan word; it may be a typo or abbreviation.
In this sentence, 'oscil·lació' (derived from 'oscil·lar') is used as a noun describing the regular motion of the pendulum.
L'oscil·lació del pèndol és constant i regular.
The oscillation of the pendulum is constant and regular.
Here, 'oscil·len' is a verb form of 'oscil·lar' to describe the variation or fluctuation between two points.
Aquestes opinions oscil·len entre dos extrems.
These opinions oscillate between two extremes.
In this example, 'oscil·lava' is used in the past tense to convey a wavering or fluctuation in someone's voice.