euthanize vs euthanise

euthanize and euthanise both are verbs.

Word	Noun	Adjective	Verb	Adverb
euthanize	No	No	Yes	No
euthanise	No	No	Yes	No

As verbs, euthanize and euthanise are synonyms defined as:

euthanize and euthanise: intentionally cause the painless death of a person or animal

Other synonyms of euthanize include euthanatise, euthanatize, mercy kill.

euthanize (verb)	euthanise (verb)
intentionally cause the painless death of a person or animal	intentionally cause the painless death of a person or animal