Practically means "nearly," like being practically broke if you have three dollars left in the whole world. It also means "done in a practical way" — if you wear sneakers on a long walk, you’re dressed practically.
There are two main senses of practically. If you have practically no free time, you have nearly no free time. If your hair is practically blonde, it is almost blonde. Also, this word can refer to the sense of practical as sensible and realistic. A smart worker will know how to get the job done practically (efficiently). A smart investor will invest money practically (wisely). Doing things practically is the opposite of being reckless and unrealistic.