Come learn 2000+ kanji and 6000+ vocabulary words with WaniKani.
Remember how 不孝 is "disobedience to parents"? Well, someone who shows disobedience to parents is a disobedient child or an unfilial child.
不孝 is a reading you should know already. Add the もの reading for 者 and you have yourself a reading. Now go be obedient to your parents and keep studying your kanji.
My mother called me a "disobedient child."