is (blank) a valid word

That thing you always search after playing a round of boggle or after making a word in scrabble to see if you really got that point for that word.

Grandma: Are you sure that's a word?
You: Yes grandma, lozt is a word
Grandma: I will get the old dictionary to check
You: No grandma I will search online
You on your device: is (blank) a valid word