headful vs containerful

headful and containerful both are nouns.

Word	Noun	Adjective	Verb	Adverb
headful	Yes	No	No	No
containerful	Yes	No	No	No

As nouns, containerful is a hypernym of headful; that is, containerful is a word with a broader meaning than headful:

headful (noun)	containerful (noun)
a covering over the surface of your head	the quantity that a container will hold
the quantity of information that a head will hold