Abbreviation of teaspoon.
"The computer science textbook dedicates an entire chapter to analyzing algorithms for the tsp, or travelling salesman problem."
Initialism of travelling salesman problem.
In plain English: A teaspoon is a small spoon used for eating, cooking, and measuring tiny amounts of ingredients.
"She added two teaspoons of sugar to her coffee."
Initialism of Thrift Savings Plan.
"After retiring, he transferred his remaining funds from his 401k into a TSP to maximize his tax-deferred growth."