Verb (5-dan, す, transitive)
1. to add (numbers)
七と七を足してください。Please add seven and seven.
2. to add (something); to top up (with something)
なんで水を足すんですか。Why are you adding water?
3. to take care of (e.g. one's business)
お前はさっさと用でも足してこい。You, hurry up and go take care of your business.