orb vs time-ball

orb and time-ball both are nouns.

Word	Noun	Adjective	Verb	Adverb
orb	Yes	No	Yes	No
time-ball	Yes	No	No	No

As nouns, time-ball is a hyponym of orb; that is, time-ball is a word with a more specific, narrower meaning than orb:

orb: an object with a spherical shape
time-ball: a ball that slides down a staff to show a fixed time; especially at an observatory

Other hyponyms of orb include crystal ball, camphor ball, mothball, fireball, fireball, globule, spherule, pellet, bolus.

orb (noun)	time-ball (noun)
the ball-shaped capsule containing the vertebrate eye	a ball that slides down a staff to show a fixed time; especially at an observatory
an object with a spherical shape

orb (verb)	time-ball (verb)
move in an orbit