to dilate  - dilatar, dilatarse 

to widen  - ampliar, ensanchar, ampliarse, ensancharse 

to expand  - ampliarse, extenderse, expandir, dilatar, aumentar, ampliar, expandirse, dilatarse (dícese de los metales, gases, etc.), extender 

to put off

to postpone  - postergar, aplazar, posponer