WordWeb Online

1. Weak from exhaustion
   - flagging
    
2. Hanging down (as from exhaustion or weakness)
   - droopy, sagging
    
3. Having branches or flower heads that bend downward
   "lilacs with drooping panicles of fragrant flowers"
   - cernuous, nodding, pendulous, weeping

1. Droop, sink, or settle from or as if from pressure or loss of tautness
   - sag, swag, flag
    
2. Hang loosely or laxly
   - loll
    
3. Become limp
   - wilt

See also: droopingly, lax, tired, unerect

Type of: crumble, dangle, decay, dilapidate, drop, drop down, sink, swing