If a student earns a letter in sports or athletics by being part of the university or college team, they are entitled to wear on their jacket the initial letter of the name of their university or college. Valerie earned letters in three sports: volleyball, basketball, and field hockey
an award earned by participation in a school sport; "he won letters in three sports"
Items that measure at least 140 x 90 mm (A6) and at most 353 x 250 mm (B4), with a maximum thickness of 50 mm and maximum weight of 1000 g, are treated as letters Within this category, we differentiate between "Letters", "Large letters" and "Maxi letters" (format categories) Smaller formats are treated as special items, larger formats as parcels
If you write a letter to someone, you write a message on paper and send it to them, usually by post. I had received a letter from a very close friend. a letter of resignation Our long courtship had been conducted mostly by letter
a written message addressed to a person or organization; "mailed an indignant letter to the editor"
If you say that someone carries out instructions to the letter, you mean that they do exactly what they are told to do, paying great attention to every detail. She obeyed his instructions to the letter