noun
plural phases
[count] :a part or step in a process :one part in a series of related events or actions
[count] :a short period of time during which a person behaves in a particular way or likes a particular thing
[count] :the shape of the part of the moon that is visible at different times during a month
[noncount] Brit :the state in which things work together with each other - used in the phrases in phase or out of phase
verb
phases; phased; phasing
phase in
[phrasal verb]
phase (something) in or phase in (something) :to start to use or do (something) gradually over a period of time :to introduce (something) slowly
phase out
[phrasal verb]
phase (something) out or phase out (something) :to stop using, making, or doing (something) gradually over a period of time