Parents and Children

BROBDINGNAGIAN and LUMBERING both contain BIG.
CLOSEMOUTHED and UNCOMMUNICATIVE both contain MUTE.
EXHILARATION AND EXULTATION both contain ELATION.
FOUNDATION and FOUNTAIN both contain FONT.
IMPAIR and MALFORM both contain MAR.
IRRITATED and INFURIATED both contain IRATE.
JOINED and CONFEDERATED both contain ONE.
JOLLITY and JOCULARITY both contain JOY.
LATEST and LEAST both contain LAST.
LIGHTED and ILLUMINATED both contain LIT.
NOUGAT and NEUROTIC both contain NUT.
OBSERVE and SPECTATE both contain SEE.
PLAYFULNESS and FACETIOUSNESS both contain FUN.
POSTURED and POSITIONED both contain POSED.
PURGED and PASTEURIZED both contain PURE.
RAMPAGE and RAVAGE both contain RAGE.
UNANIMITY and UNIFORMITY both contain UNITY.
SLIPPERY, STEALTHY, and SLINKY all contain SLY.
TRANSGRESSIONS, PERVERSIONS, and MISDOINGS all contain SINS.