1 xz is a command line tool with syntax similar to that of gzip. 2  xzdec is a decompression-only tool smaller than the full-featured xz tool. 3  A set of shell scripts (xzgrep, xzdiff, etc.) have been adapted from gzip to ease viewing, grepping, and comparing compressed files.
Epoch (astronomy), a moment in time used as a reference for the orbital elements of a celestial body. Epoch (cosmology) or cosmologic epoch, a phase in the development of the universe since the Big Bang. Epoch (geology) or geologic epoch, a span of time smaller than a period and larger than an age.
dawn - an opening time period; it was the dawn of the Roman Empire. figure of speech, trope, image, figure - language used in a figurative or nonliteral sense. period, period of time, time period - an amount of time; a time period of 30 years; hastened the period of time of his recovery; Picasso's blue period.