The word low-fat is an adjective. It describes something that does not have a high number of calories.
If two yogurts are exactly the same, except for one's being lowfat and the other being nonfat, the lowfat product would be more filling.
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
what part of speech is beneath
adverb
The part of speech for "explicit" is an adjective.
The part of speech for "lecturer" is a noun.
The part of speech for "rapid" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "breezy" is an adjective.
The part of speech for "buried" is a verb.