If you are talking about Thai food with foreigner, the words you will here are 'Tom Yum Kung' , 'Som Tum' or 'Pad Krapraw' (fried chicken or pork with basil leaves.) . And their taste are spicy.

Taste of Thai food in foreigner's opinion is spicy food. All of the spicy taste is from 'Prik' (chilli). There are many types of Prik in Thailand. And the most famous of Thailand for the world is 'Prik Keenuu' (Chilli Padi, Bird's Eye Chilli, Bird Chilli, Thai pepper). Prik has many properties. It can help you to digest your food and cure pains in your stomach or intestine. Many foreigners try to eat the spicy Thai food because it's charm of Thailand. Although spicy is famous taste of Thailand but there are many Thai paople don't like spicy taste.