subdivide
verb (used with object)
to divide (that which has already been divided) into smaller parts; divide again after a first division.
Used to describe an ongoing action or continuous state that was happening at a specific time in the past.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
She was subdividing the country into its narrowest possible parts and trying to conquer them one by one.
From The New Yorker ● May 1, 2017