vaga-, vag-, vago- +

(Latin: wander, move around; unsettled, wandering [nerve])

vagrant (s), vagrants (pl) (nouns)
1. A wanderer who has no permanent place to live.
2. Those who never stay in one place for very long.
3. Anyone who is guilty of the legal offense of living on the streets and, in some jurisdictions, begging.
vague, vaguer, vaguest (adjectives)
1. Not clear in meaning or intention: "The travel agent made a vague schedule for our tour."
2. Not having a clear or perceptible form: "We could only see the vaguest form in the shadows of the forest."
3. Not clearly felt, understood, or recalled: "My mother only had a vague recollection of what happened."
4. Unclear or incoherent in thinking or expression.
5. Etymology: from Middle French vague, from Latin vagus, "wandering, rambling, vacillating".
vagueness (s) (noun)
1. Lacking definiteness or precision, or not easily understood.
2. A communication pattern involving the use of global pronouns and loose associations that lead to ambiguity and confusion in communication.
3. The phenomenon that the meaning of an expression is not exactly determined, as a result of the impreciseness of natural language.

In "John is tall", the meaning of the adjective "tall" is vague, or unclear, in the sense that the precise degree of tallness is not specific.

Vagueness should not to be confused with ambiguity, even though the two are not always clearly distinguishable by some speakers or writers.

vagulate, vagulates; vagulated; vagulating (verbs)
To wander or to waver: "The man was vagulating in the park in a vague manner because of the recent loss of his wife as a result of cancer."
vagus (s), vagi (pl) (nouns)
1. A mixed nerve that supplies the pharynx and larynx and lungs and heart and esophagus and stomach and most of the abdominal viscera.
2. Either of the tenth pair of cranial nerves that carry sensory and motor neurons serving the heart, lungs, stomach, intestines, and various other organs.
3. Wandering; applied especially to the pneumogastric nerve.
vagus nerve (s), vagus nerves (pl) (nouns)
A mixed nerve that arises by numerous small roots from the side of the medulla oblongata, between the glossopharyngeal above and the accessory below.

It leaves the cranial cavity by the jugular foramen and passes down to supply the pharynx, larynx, trachea, lungs, heart, and the gastrointestinal tract as far as the left colic (splenic) flexure; the only cranial nerve that does not arise from the brain, but is classified as such because it exits from the cranium.

vagus pulse, vagus-pulse (s) (noun)
1. A slow, regular pulse caused by an over activity of the vagus nerve.
2. Decreased heart rate caused by the slowing action of stimuli from the vagus nerve.