eat up in WordNet English dictionary

1. enclose or envelop completely, as if by swallowing
   "The huge waves swallowed the small boat and it sank shortly thereafter"
   immerse  swallow  swallow up  bury  eat up 
   
2. use up (resources or materials)
   "this car consumes a lot of gas"; "We exhausted our savings"; "They run through 20 bottles of wine a week"
   consume  eat up  use up  eat  deplete  exhaust  run through  wipe out 
   
3. finish eating all the food on one's plate or on the table
   "She polished off the remaining potatoes"
   eat up  finish  polish off 
   

eat up in English Wiktionary