Hi ,in portuguese Someone that is "mudo" it is a person that can not speak or hear . For word "Müde" I can imagine that guy is so tired that he can't speak or hear .
I tend to use silly tricks to remember how a word begins, then the rest of it kinda "kicks in"... I imagine a tired cow (moo)
Typically they end in 'e' or describe a female version of something (e.g. die Präsidentin is a female president where der Präsident is a male president).