alternation of generations
daimyo's alternating Edo residence; official attendance service (by a daimyo in the Edo period)
change of government; regime change
day and night shift work schedule
replacing the old with the new; the old giving way to the new
substitute player; substitution
alternation of nuclear phases
ablaut; vowel gradation; apophony; vowel shift
alternate track; alternative track
phonological alternation; sound alternation; phonetic alternation