v.
   - travel some distance between one's home and place of work on a regular basis.
 - reduce (a judicial sentence, especially a sentence of death) to a less severe one. 
▸change one kind of payment or obligation for (another).
 ▸replace (an annuity or other series of payments) with a single payment.
 - Mathematics  (of two operations or quantities) have a commutative relation.
 
 
  Derivative
  
    - commutable adj.
  - commuter n.
 
   
  Etymology
  ME: from L. commutare, from com- ‘altogether’ + mutare ‘to change’; sense 1 derives from commutation ticket, the US term for a season ticket (because the daily fare is commuted to a single payment).