headache vs encumbrance

headache and encumbrance both are nouns.

Word	Noun	Adjective	Verb	Adverb
headache	Yes	No	No	No
encumbrance	Yes	No	No	No

As nouns, encumbrance is a hyponym of headache; that is, encumbrance is a word with a more specific, narrower meaning than headache:

Other hyponyms of headache include bugaboo, burden, incumbrance, load, onus, business.

headache (noun)	encumbrance (noun)
something or someone that causes anxiety; a source of unhappiness	any obstruction that impedes or is burdensome
pain in the head caused by dilation of cerebral arteries or muscle contractions or a reaction to drugs	an onerous or difficult concern
	a charge against property (as a lien or mortgage)