A more thorough explanation:

A tenement house is a type of apartment building that is usually in poor condition and only meets minimal safety and sanitary standards. It is often rented out to people who cannot afford better housing options.

For example, a tenement house might have small, cramped apartments with no windows or ventilation. The plumbing and electrical systems might be outdated and dangerous. The building might not have proper fire escapes or sprinkler systems.

Another example of a tenement house is the famous "dumbbell" tenements that were built in New York City in the late 19th and early 20th centuries. These buildings were designed to maximize the number of apartments that could fit on a small lot, but they were often overcrowded and unsanitary.

These examples illustrate the definition of a tenement house by showing how they are typically low-quality, unsafe, and unsanitary housing options for people who cannot afford better.