IPA: /ˈsloʊθfəl/
KK: /ˈsloʊθfəl/
Not willing to work or put in effort; lazy.
He was too slothful to get out of bed and go for a run.
Comparative: more slothful
Superlative: most slothful
Slothful is formed from "sloth" (from Old English *slæwð*, meaning laziness or sluggishness) and "-ful" (meaning full of). The word "slothful" means full of sloth or characterized by laziness.
Think of 'sloth' as representing laziness, and remember that 'slothful' means being full of that laziness.