Copters
Leather
Cheetah
seduces
bellhop
therein
The seven-letter word that contains 10 different words without rearranging any letters is "therein." The words that can be formed using the letters of "therein" are: the, there, herein, herein, here, there, ere, rein, in, and he.
bellhop
therein
bellhop
therein
A synonym of "friendy" that contains 7 letters is affable. :)
secular