1. A flow that returns toward its source
   - backflow

Type of: flow, flowing

• unceasing
• unceasingly
• uncensored
• unceremonial
• unceremonious
• unceremoniously
• unceremoniousness
• uncertain
• uncertainly
• uncertainness
• uncertainty
• uncertainty principle
• uncertified
• unchain
• unchained
• unchallengeable
• unchallenged
• unchangeability
• unchangeable
• unchangeableness
• unchangeably
• unchanged
• unchanging
• unchangingness
• unchaperoned