stepladder vs ladder

stepladder and ladder both are nouns.

Word	Noun	Adjective	Verb	Adverb
stepladder	Yes	No	No	No
ladder	Yes	No	Yes	No

As nouns, ladder is a hypernym of stepladder; that is, ladder is a word with a broader meaning than stepladder:

stepladder: a folding portable ladder hinged at the top
ladder: steps consisting of two parallel members connected by rungs; for climbing up or down

stepladder (noun)	ladder (noun)
a folding portable ladder hinged at the top	steps consisting of two parallel members connected by rungs; for climbing up or down
	a row of unravelled stitches
	ascending stages by which somebody or something can progress

stepladder (verb)	ladder (verb)
	come unraveled or undone as if by snagging