var strs = ["run", "frun", "frun and run", "runf", "Run", "Run away", "frun is frun"];
var reg = /\b(run)\b/i;
for(var i=0;i<strs.length;i++) {
if(reg.test(strs[i])) console.log("String '"+ strs[i] + "' consists of word 'run'");
else console.log("String '"+ strs[i] + "' NOT consists of word 'run'");
}