Etymology From New Latin phasis, from Ancient Greek φάσις (phásis, “an appearance”), from φαίνω (phaínō, “to cause to appear”); compare phantasm and see face.
A distinguishable part of a sequence or cycle occurring over time.
It would have been a simple enough move to warn the firm, but Max Carrados's interest lay in the phase of crime rather than in forestalling it, and on that score he had little tangible as yet […]1934, Ernest Bramah, The Bravo of London:
2
That which is exhibited to the eye; the appearance which anything manifests, especially any one among different and varying appearances of the same object.
3
Any appearance or aspect of an object of mental apprehension or view.
The problem has many phases.
4
Astronomy, Natural sciences A particular appearance or state in a regularly recurring cycle of changes with respect to quantity of illumination or form, or the absence, of a body's illuminated disk. Illustrated in Wikipedia's article Lunar phase.
the phases of the moon
5
Natural sciences, Physical sciences, Physics Any one point or portion in a recurring series of changes, as in the changes of motion of one of the particles constituting a wave or vibration; one portion of a series of such changes, in distinction from a contrasted portion, as the portion on one side of a position of equilibrium, in contrast with that on the opposite side.
6
Chemistry, Natural sciences, Physical sciences A component in a material system that is distinguished by chemical composition and/or physical state (solid, liquid or gas) and/or crystal structure. It is delineated from an adjoining phase by an abrupt change in one or more of those conditions.
7
Biology, Natural sciences, Zoology In certain organisms, one of two or more colour variations characteristic of the species, but independent of the ordinary seasonal and sexual differences, and often also of age.
8
The period of play between consecutive breakdowns.
When Romania did manage to string together some phases midway through the first half, England's discipline held firm, although on the whole it was a less focused display from the Six Nations champions in the second half.2011 September 24, Ben Dirs, “Rugby World Cup 2011: England 67-3 Romania”, in BBC Sport:
Mathematics, Sciences The counterclockwise angle from the positive half of the real number line to the vector pointing to a complex number on an Argand diagram of the complex plane, which has the positive real line pointing right and the positive imaginary number line pointing up.
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Entertainment, Lifestyle, Music A distortion caused by a difference in the speed of propagation for different frequencies
Etymology From New Latin phasis, from Ancient Greek φάσις (phásis, “an appearance”), from φαίνω (phaínō, “to cause to appear”); compare phantasm and see face.
1
With in or out To begin—if construed with "in"—or to discontinue—if construed with out—(doing) something over a period of time (i.e. in phases).
The use of the obsolete machines was gradually phased out as the new models were phased in.
Anyone who has lost their way in cyberspace—realizing they have just phased into what they had previously categorized as 'solid' matter—will understand this example.1997, P. Lunenfeld, “Hybrid Architectures and the Paradox of Unfolding”, in Intelligent Environments: Spatial Aspects of the Information Revolution, →ISBN, page 443:
Archer took a deep breath and, steeling himself for the bizarre experience, carefully walked to the bulkhead and phased through.2004, Paul Ruditis, Star Trek: Enterprise: Shockwave, →ISBN, page 100:
1 more example
Intangible or invisible objects in comic books are often drawn with a dotted line. When Kitty Pryde of the X-Men phases through objects, she's drawn that way, and Wonder Woman's invisible plan[sic] used to be drawn that way as well.2011, Timothy Callahan, Grant Morrison: The Early Years, →ISBN, page 93: