The crossword solution for the term 'WHAT AN INFINITE LOOP LACKS' is ENDS, which has 4 letters. An infinite loop is a programming construct that causes a program to repeat an instruction sequence indefinitely. It is often caused by a condition that can never be met, such as when a counter is incremented but never reaches a desired value. As a result, an infinite loop lacks an end point, which is why the crossword solution is ENDS.