How to kick if a player says an innapropiate word?

I see that the other answer suggested using an array, but the issue with this is that it would take far too long to include all "hashtagged" words that the ROBLOX Chat System detects.

Fear not, for ROBLOX has a service that has filter functionality. You will need to have the LocalPlayer defined first.

You'd use:

local textService = game:GetService("TextService");
local text = textService:TextFilterContext(message, player.UserId, 1); -- replace message with your message, and player.UserId with the UserId of the player. This will filter the text based on the player's settings. The 1 is context. 1 = PublicChat, 2 = PrivateChat.

Learn more about TextService here: https://developer.roblox.com/en-us/api-reference/class/TextService

After filtering, check if the string is hashtagged and kick the player.

i see what you mean you want to have it check if the player says the message i explained more below

local list = {"stupid", "trash", "clapped", "claped", "stoopid"} --Contains inappropriate words.
function checkString(message)
    for i,v in pairs(list) do --Go through the list
        if v:lower() == message:lower() then --Check if the message is the same as a word in the list
            return true
        end
    end
end

game.Players.PlayerAdded:connect(function(Player) --When a player joins
    Player.Chatted:connect(function(Message) --When the player chats
        if checkString(Message) then --If what they chatted was inappropriate
            Player:Kick("\n\nYou Said An Innapropiate Word In Our Game!\n\n") --Kick them from the game.
        end
    end)
end)