intransitive verbos·cil·lat·ed, os·cil·lat·ing, os·cil·lates
- To swing back and forth with a steady, uninterrupted rhythm.
- To waver, as between conflicting opinions or courses of action; vacillate: “The court has oscillated over the decades from more liberal to less, more conservative to less, depending upon who was president at the time of vacancies” ( Gordon J. Humphrey ) See Synonyms at swing.
- Physics To vary between alternate extremes, usually within a definable period of time.
Origin of oscillate
Latin ōscillāre ōscillāt- from ōscillum something that swings back and forth, swing probably from ōscillum small mask of Bacchus diminutive of ōs mouth
; see ōs-
in Indo-European roots.
The history of the word oscillate
shows how English words referring to technical or scientific concepts often come from Latin words describing everyday objects and ordinary life in ancient times. In a passage in his Georgics,
a long poem celebrating rural life, the Roman poet Virgil describes how Bacchus is honored in the countryside by hanging small masks from pine trees. He uses the Latin word ōscillum
) to refer to these hanging religious decorations, which were common in the ancient Roman world. The house of a wealthy Roman family was usually built around one or more courtyards or gardens enclosed by rows of columns, and in each space between these columns, an ōscillum
was often hung. It is probable that this word ōscillum,
“something that swings back and forth,” is simply an extended use of the word ōscillum
meaning “a small mouth, a small face” (a diminutive of ōs,
“mouth”), since the swinging objects most often consisted of masks or tondi depicting faces. From the word ōscillum,
“something that swings back and forth,” the Romans derived the verb ōscillāre,
“to ride in a swing,” and the noun ōscillātiō,
“the action of swinging.” These are the sources of English oscillate
words that entered English during the 1600s and 1700s as technical terms mainly used in scientific writings and similar works.
(third-person singular simple present oscillates, present participle oscillating, simple past and past participle oscillated)
- (intransitive) To swing back and forth, especially if with a regular rhythm.
- A pendulum oscillates slower as it gets longer.
- (intransitive) To vacillate between conflicting opinions, etc.
- The mood for change oscillated from day to day.
- (intransitive) To vary above and below a mean value.
From Latin oscillatus perfect passive participle of Latin oscillÅ (“swing"), from oscillum (“a swing"), usually identified with oscillum (“a little face or mask hung to a tree and swaying with the wind"), diminutive of os (“mouth, face").