The action of biting and grinding food with your teeth into smaller pieces before swallowing.
From Old English ceow, related to German kauen. The word has existed in English for over a thousand years and originally simply meant the mechanical action of teeth breaking down food.
Humans are actually not very efficient chewers compared to other animals—cows chew their cud (regurgitate and rechew food) to break down plant material, while dogs can barely chew at all, which is why they're so dangerous when they swallow things whole.
Complete word intelligence in one call. Free tier — 50 lookups/day.