block anaesthesia vs anesthesia

block anaesthesia and anesthesia both are nouns.

Word	Noun	Adjective	Verb	Adverb
block anaesthesia	Yes	No	No	No
anesthesia	Yes	No	No	No

As nouns, anesthesia is a hypernym of block anaesthesia; that is, anesthesia is a word with a broader meaning than block anaesthesia:

block anaesthesia: anesthesia of an area supplied by a nerve; produced by an anesthetic agent applied to the nerve
anesthesia: loss of bodily sensation with or without loss of consciousness

Other hypernyms of block anaesthesia include anaesthesia.

block anaesthesia (noun)	anesthesia (noun)
anesthesia of an area supplied by a nerve; produced by an anesthetic agent applied to the nerve	loss of bodily sensation with or without loss of consciousness