What do the following words have in common?
HAGGARD
SWELTERING
HOGBACK
DOWNDRAFT
BIBLIOPHILE
DEVILMENT
FLEET
IRTRONS
Adding last three letters with the first produces a new word.
Thus,
HAGGARD-----------> HARD
SWELTERING-------> SING
HOGBACK----------> HACK
DOWNDRAFT------> DAFT
BIBLIOPHILE.......> BILE
DEVILMENT.........> DENT
FLEET--------------> FEET
IRTRONS----------> IONS