Other hyponyms of idler include
clock watcher,
couch potato,
dallier,
dilly-dallier,
dillydallier,
lounger,
mope,
dawdler,
drone,
laggard,
lagger,
poke,
trailer,
daydreamer,
woolgatherer,
goldbrick,
good-for-naught,
good-for-nothing,
goof-off,
ne'er-do-well,
no-account,
lazybones,
lie-abed,
slugabed,
loon,
shirker,
slacker,
slug,
spiv,
sunbather,
trifler,
whittler.