top boot vs half boot

top boot and half boot both are nouns.

Word	Noun	Adjective	Verb	Adverb
top boot	Yes	No	No	No
half boot	Yes	No	No	No

As nouns, top boot and half boot are synonyms defined as:

Other synonyms of top boot include buskin, combat boot, desert boot.

top boot (noun)	half boot (noun)
a boot reaching halfway up to the knee	a boot reaching halfway up to the knee