使 (shǐ) is a formal/literary verb meaning 'to cause, to make (someone do something)' — it's the written equivalent of 让 (ràng) in speech. It also means 'to use, to employ' in formal contexts, overlapping with 使用 (shǐyòng), but 使 is more concise and literary, while 使用 is the standard everyday verb for 'to use'.