Extremity, n.; pl. Extremities(.
Etymology: [L. extremitas: cf. F. extrémité.]
1. The extreme part; the utmost limit; the farthest or remotest point or part; as, the extremities of a country. They sent fleets . . . to the extremities of Ethiopia. Arbuthnot.
2. (Zoöl.)
One of locomotive appendages of an animal; a limb; a leg or an arm of man.
3. The utmost point; highest degree; most aggravated or intense form. "The extremity of bodily pain." Ray.
2 more senses
4. The highest degree of inconvenience, pain, or suffering; greatest need or peril; extreme need; necessity. Divers evils and extremities that follow upon such a compulsion shall here be set in view. Milton. Upon mere extremity he summoned this last Parliament. Milton.
Syn. -- Verge; border; extreme; end; termination.
Shades of meaning
Fernald has no entry of its own for extremity; he lists it under end, necessity.
Where he writes about it:
The end is the terminal part of a material object that has length; the extremity is distinctively the terminal point, and may thus be but part of the end in the general sense of that word; the extremity is viewed as that which is most remote from some center, or some mean or standard position; the southern end of South America includes all Patagonia, the southern extremity or point is Cape Horn. — from end
Tip has nearly the same meaning as extremity, but is said of small or slight and tapering objects; as, the tip of the finger; point in such connections is said of that which is drawn out to exceeding fineness or sharpness, as the point of a needle, a fork, or a sword; extremity is said of something considerable; we do not speak of the extremity of a needle. — from end