mollykins, your chemistry teacher is very mistaken. Hydrophobic is a word that is used in both chemistry, biology and biochemistry. While it's probably used more in biological sciences, the concept is something that is taught to chemistry "A" levels students as well as those undertaking a chemistry degree.
I think you and I have discussed before the shortcomings of your teachers and to my mind, this is another one. Where is your school getting them from? These people should really make every effort to get their facts right.
Here's what we'll do: the next time your chemistry teacher tells you that hydrophobic is inappropriate to use in chemistry, ask your teacher "then can you explain to me what these hydrophobic colloids I've read about really are?" A "hydrophobic colloid" is a term that all chemistry graduates should know about.
You can also tell him/her that you've read on the internet that iron (iii) hydroxide Fe(OH)3 forms a hydrophobic colloid in water. Ask if it's true and watch the reaction..