defenselessly vs defenceless

defenselessly is not an adjective while defenceless is an adjective.

Word	Noun	Adjective	Verb	Adverb
defenselessly	No	No	No	Yes
defenceless	No	Yes	No	Yes

As adverbs, defenselessly and defenceless are synonyms defined as:

Other synonyms of defenselessly include defencelessly, defenseless.

defenselessly (adjective)	defenceless (adjective)
	lacking weapons for self-defense
	lacking protection or support

defenselessly (adverb)	defenceless (adverb)
without defense	without defense