Unworthy means not deserving the respect, or the thing, in question. Falling short of what was expected.
It takes of, so unworthy of the honour, unworthy of the name. There is a particular British construction where it is used about behaviour, since saying that a remark was unworthy of somebody means they are better than that, and it is a rebuke dressed as a compliment. The word carries a faintly religious flavour from centuries of prayer. Its opposite, worthy, has itself drifted towards meaning dull but well-meaning.
1adjectiveunworthyNot deserving respect, attention or a particular thing.
“That remark was unworthy of you.”
Middle English
unworthy
English, today
unworthy
From Middle English unworthy, equivalent to un- + worthy.
Etymology from Wiktionary, CC BY-SA