Lakeland vs Lake District

Lakeland and Lake District both are nouns.

Word	Noun	Adjective	Verb	Adverb
Lakeland	Yes	No	No	No
Lake District	Yes	No	No	No

As nouns, Lakeland and Lake District are synonyms defined as:

Lakeland and Lake District: a popular tourist area in northwestern England including England's largest lake and highest mountain

Lakeland (noun)	Lake District (noun)
a popular tourist area in northwestern England including England's largest lake and highest mountain	a popular tourist area in northwestern England including England's largest lake and highest mountain