dozens; scores of; decades
second (unit of time); arc second
unit (e.g. meters, grams, etc.); denomination; unit (i.e. one comprised of many); group; credit (in school, university, etc.); point
one day; all day (long); the whole day; first day of the month
unrealistic; impractical; infeasible; unreal
to need; to call for; to require
routine; routine duties; routine work; routine
the most; the extreme; prime; conspicuous
early days; early years; early stages; initial stages; beginning
general-purpose; all-purpose; one-size-fits-all
period; epoch; the times; those days; oldness; ancientness
individual; one by one; separate; each
to be needed; to be necessary; to be required; to be wanted; to need; to want
selection; making a choice; sifting; decision to adopt or reject
before very long; soon; someday; of the previously mentioned; of that number; among them
to fly; to soar; to jump; to leap; to spatter; to scatter; to hurry
first of all; at once; for now; for the time being; anyway; at least
important matter; requirement; requisite; necessary condition
if only (you) have; as long as (you) have; whenever (you) have
distinction; differentiation; discrimination; difference
in itself; the thing itself; this itself; for its own sake; per se
to be based on; to take into account; to build upon; to have one's feet firmly planted on; to plant oneself on
charm; incantation; spell; code that is not (yet) necessary to understand; required boilerplate code
built-in function (e.g. in programming language)
indispensable; essential; requisite; required; compulsory; necessary
to have meaning; to be meaningful
at this juncture; after all this time; at this stage; now
old-fashioned; behind the times; out-of-date; antiquated
wise; clever; smart; well-behaved (esp. children and pets); obedient; good
to be sufficient; to be enough; to be worth doing; to be worthy of; to do (the job); to serve