Cases of word usage

1) theoretical (and not thinking about practical problems) (doctrinaire)

2) (of a person) practical and realistic (down-to-earth)

3) having, designed to have, practical use (functional)

4) a small mechanical apparatus for a particular practical use (gadget)

5) practical ability through experience (know-how)

6) a short statement offering practical advice based on experience about how to live etc, as in 'Look before you leap' (maxim)

7) in a practical manner; almost (practically)

8) (a detail concerning) the condition of being practical (practicality)

9) the belief that the truth or value of a theory depends on its practical use (pragmatism)

10) practical and based on actual facts, not theory (realistic)