epoch
- 01 C1 Advanced
n.a long period of time in history that is important because of specific events or changes.
n.a distinct period in history or a person's life, typically marked by notable events or a particular state of affairs.
Simple“The invention of the steam engine marked a new epoch in industrial history.”
In context“Historians often argue that the fall of the Berlin Wall signaled the end of a geopolitical epoch defined by the Cold War.”
- 02 C2 Proficiency
n.a unit of time used by scientists to describe millions of years in Earth's history.
n.a geochronologic unit of time, typically lasting millions of years, representing a subdivision of a period.
Simple“We are currently living in the Holocene epoch, which began after the last ice age.”
In context“The transition between the Eocene and Oligocene epochs is marked by significant global cooling and changes in marine life.”
Synonyms - 03 C2 Proficiency
n.the exact date and time that a computer system uses to start counting time.
n.a fixed point in time used as a reference from which time is measured in a computing system.
Simple“The Unix epoch began at midnight on January 1, 1970.”
In context“The system clock calculates the current time by counting the number of seconds elapsed since the designated epoch.”
UsageOften used with 'the' as a proper noun in specific contexts like 'the Unix epoch'.
Synonymsreference point - 04 C2 Proficiency
n.one full cycle of training an AI using all the available data.
n.one complete pass of the entire training dataset through a machine learning algorithm.
Simple“The model's accuracy improved significantly after the tenth epoch of training.”
In context“Training was halted after fifty epochs to prevent the neural network from overfitting the training data.”
- 05 C2 Proficiency
v.to divide a long recording of data into smaller pieces based on time.
v.to segment continuous data, such as an EEG recording, into specific time-locked windows for analysis.
Simple“The researcher had to epoch the brainwave data to analyze the response to each sound.”
In context“The raw signal was epoched into two-second intervals relative to the onset of the visual stimulus.”
“The Pleistocene epoch lasted from around 2.58 million years ago until 11,700 years ago.”
From Medieval Latin epocha, from Ancient Greek ἐποχή (epokhḗ, “a check, cessation, stop, pause, epoch of a star, i.e., the point at which it seems to halt after reaching the highest, and generally the place of a star; hence, a historical epoch”), from ἐπέχω (epékhō, “I hold in, check”), from ἐπι- (epi-, “upon”) + ἔχω (ékhō, “I have, hold”). Doublet of epoche.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.