designer vs landscapist

designer and landscapist both are nouns.

Word	Noun	Adjective	Verb	Adverb
designer	Yes	No	No	No
landscapist	Yes	No	No	No

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

designer: someone who creates plans to be used in making something (such as buildings)
landscapist: someone who arranges features of the landscape or garden attractively

Other hyponyms of designer include landscape architect, landscape gardener, landscaper, Ithiel Town, Town.

designer (noun)	landscapist (noun)
someone who creates plans to be used in making something (such as buildings)	someone who paints landscapes
someone who designs clothing	someone who arranges features of the landscape or garden attractively
a person who specializes in interior design
a person who devises plots or intrigues
someone who specializes in graphic design