The phrase "to tie out" means to secure or fasten something, typically an animal, so that it cannot move freely. This can be done by using a leash, harness, rope, or other restraints to restrict movement in one direction or another. The term is commonly used when referring to securing dogs outside, either on a lead or within a fenced area, so they are unable to wander off or cause damage. It can also refer to tying down objects, such as boats or trailers, to keep them stable and prevent them from moving unexpectedly.