WordWeb Online

1. Perform without preparation
   "he improvised a speech at the wedding";
   - improvize [non-standard], ad-lib, extemporize, extemporise [Brit], wing [informal], wing it [informal]
    
2. Manage in a makeshift way; do with whatever is at hand
   "after the hurricane destroyed our house, we had to improvise for weeks";
   - extemporize, extemporise [Brit]

Derived forms: improvised, improvising, improvises

Type of: contend, cope, deal, do, execute, get by, grapple, make do, manage, perform

Encyclopedia: Improvise Improvise, adapt and overcome