From fire (“four”) and spring (“jump”). <span class="searchmatch">firspring</span> n only used in i fuldt <span class="searchmatch">firspring</span>....
i fuldt <span class="searchmatch">firspring</span> at a gallop at full pelt, at full tilt...
indefinite spring) (athletics, gymnastics) spring, jump, vault, leap <span class="searchmatch">firspring</span> højdespring længdespring springavancement springbane springbræt springkniv...