The best replacement for requirement is specification.

The best alternatives to requirement are rated as following:
★★★★★  specification
★★★  requirements
★★★  constraint
★★  feature
★★  business rule
★★  use case
★★  user story
★★  requisite
★★  capability
★★  functional requirement
★★  prerequisite
★  need
★  functional specification
★  non functional requirement
★  goal
★  criteria
★  user requirement
  assumption
  system requirement
  house requirement
  software requirement
  nonfunctional requirement
  business requirement
  deliverable
  salary history
  technical requirement

Your alternative for requirement is not listed? Suggest!
Speaking about requirement, one probably shouldn't forget about traverse.

Other search terms related to requirement and their ratings are:
★★★★★ traverse
★★★ resume
cover letter
booster seat
You have in mind a companion for requirement and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of requirement in all years. Click on graph for more.
requirement
specification
requirements