Whitish means having a pale or light color that's somewhat white but not purely or brightly white. A whitish fog might hang over a field in the morning, looking gray-white and hazy. Whitish clouds are lighter than storm clouds but not as bright as fluffy summer clouds. Aged paper often turns whitish-yellow rather than staying pure white.

The “-ish” suffix is useful here: it means “somewhat” or “kind of.” Just as reddish means somewhat red and tallish means kind of tall, whitish describes something that has white as its main color quality but mixed with something else. A whitish stone might have hints of gray or cream in it. Whitish paint on an old fence has faded from bright white to a duller, less pure shade.

You might describe someone's face as looking whitish if they seem pale from feeling sick or scared. Or you might notice the whitish foam that forms on top of hot chocolate before it settles. The word helps you be more precise than just saying “white” when describing something that's close to white but not quite there.