Be concise.

Be useful.

All contributions dictatorially edited by webmasters to match personal tastes.

Please do not paste any copyright violating resource.

Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations
import "strings"
lowerS, lowerWord := strings.ToLower(s), strings.ToLower(word)
ok := strings.Contains(lowerS, lowerWord)
var lowerS = s.toLowerCase();
var lowerWord = word.toLowerCase();
var ok = lowerS.indexOf(lowerWord) !== -1;
ok = s.match?( /#{word}/i )
OK := Pos(LowerCase(AWord), LowerCase(S)) > 0;
import std.string;
ok = indexOf(word, s, != -1;
import Data.Char (toLower)
import Data.List (isInfixOf)
containsIgnoreCase :: String -> String -> Bool
containsIgnoreCase s word = isInfixOf (map toLower word) (map toLower s)
ok = word.lower() in s.lower()