dawdler vs loiterer

dawdler and loiterer both are nouns.

Word	Noun	Adjective	Verb	Adverb
dawdler	Yes	No	No	No
loiterer	Yes	No	No	No

As nouns, loiterer is a hyponym of dawdler; that is, loiterer is a word with a more specific, narrower meaning than dawdler:

dawdler: someone who takes more time than necessary; someone who lags behind
loiterer: someone who lingers aimlessly in or about a place

dawdler (noun)	loiterer (noun)
someone who takes more time than necessary; someone who lags behind	someone who lingers aimlessly in or about a place