[1] : WordNet (r) 2.0

catch up
     v 1: reach the point where one should be after a delay; "i caught
          up on my homework"
     2: learn belatedly; find out about something after it happened;
        "i'm trying to catch up with the latest developments in
        molecular biology"

[2] : Moby Thesaurus II by Grady Ward, 1.0

31 moby thesaurus words for "catch up":
   abduct, carry off, catch up with, come up to, come up with,
   ensnare, entangle, entrap, fascinate, gain on, gain upon, grip,
   hold, kidnap, lap, leave behind, leave standing, mesmerize,
   outpace, outrun, outsail, outstrip, overhaul, overtake, pass,
   shanghai, snare, spellbind, tangle, throttle, trap

Ball Up >> B Words
Ball Up, definition of term: Ball Up
ball+up_pag1.html

Bang Up >> B Words
Bang Up, definition of term: Bang Up
bang+up_pag1.html

Backed Up >> B Words
Backed Up, definition of term: Backed Up
backed+up_pag1.html

Back Up >> B Words
Back Up, definition of term: Back Up
back+up_pag1.html

Ante Up >> A Words
Ante Up, definition of term: Ante Up
ante+up_pag1.html

Act Up >> A Words
Act Up, definition of term: Act Up
act+up_pag1.html