According to the Royal Institute Dictionary 1999, Thai word loi (ลอย) means “to float”, while krathong (กระทง) has various meanings, one of which is “a small container made of leaves which can be floated on water during the Loi Krathong festival”.
Loi Krathong falls on a full moon night, in November. Come the right time, Thais dress up in their best clothes and go in a place close to the water, a pond, a canal or a small lake will do, holding a little boat made of banana leaves. In the boat, they have put flowers and a candle. They light up the candle, set it afloat and make a wish while they look at the small thing going slowly away.