viscount vs Lord

viscount and Lord both are nouns.

Word	Noun	Adjective	Verb	Adverb
viscount	Yes	No	No	No
Lord	Yes	No	No	No

As nouns, Lord is a hypernym of viscount; that is, Lord is a word with a broader meaning than viscount:

Other hypernyms of viscount include noble, nobleman.

viscount (noun)	Lord (noun)
a British peer who ranks below an earl and above a baron	a titled peer of the realm
(in various countries) a son or younger brother or a count	terms referring to the Judeo-Christian God