Close-up illustration of scalpriform incisor of a beaver. It is "chisel-shaped; having the character of a chisel-tooth; truncate at the end and beveled there to a sharp edge; specifically said of the incisor teeth of rodents, and the similar teeth of a few other mammals." —Whitney, 1889

Scalpriform, Left Lower Incisor of a Beaver

Close-up illustration of scalpriform incisor of a beaver. It is "chisel-shaped; having the character…

"It is from one to four feet long, and weighs from one to twenty-five pounds. This species feed on frogs and fish, and are most active at night." — Goodrich, 1859

Sharp-Nosed Eel

"It is from one to four feet long, and weighs from one to twenty-five pounds. This species feed on frogs…

A piano keyboard.

Keyboard

A piano keyboard.

The lead can be sharpened to a chisel edge by rubbing it against a bit of sand paper or a fine file, and the corners slightly rounded.

Sharpened Pencil

The lead can be sharpened to a chisel edge by rubbing it against a bit of sand paper or a fine file,…

Scissors are hand operated cutting instruments. they consist of a pair of metal blades, or tangs, connected in such a way that the sharpened edges slide against each other.

A Pair of Scissors

Scissors are hand operated cutting instruments. they consist of a pair of metal blades, or tangs, connected…

Used for mowing and reaping, consisting of a long curved blade fixed at an angle to a long bent handle.

Attachment Scythe

Used for mowing and reaping, consisting of a long curved blade fixed at an angle to a long bent handle.

The sharp or sharpie is a long, narrow sailboat with a flat bottom used for oystering.

Sharpie

The sharp or sharpie is a long, narrow sailboat with a flat bottom used for oystering.

"A reaping hook; a curved blade of steel (anciently also of bronze) having the edge on the inner side of the curve, with a short handle or haft, for cutting with the right hand grain or grass which is grasped by the left." —Whitney, 1889
<p>This sickle has a serrated edge on the inside curve of the blade.

Sickle with Serrated Edge

"A reaping hook; a curved blade of steel (anciently also of bronze) having the edge on the inner side…

"A weapon consisting of a penetrating head attached to a long shaft of wood, designed to be thrust by or launched from the hand at an enemy or at game." &mdash;Whitney, 1889
<p>Illustration of two different hunting spears. The spear on the left has a long handle and a simple arrowhead. The spear on the right has a shorter handle and a crosspiece at the base of the blade with a curved blade attached.

Hunting Spears from the 15th or 16th Century

"A weapon consisting of a penetrating head attached to a long shaft of wood, designed to be thrust by…

"A large nail or pin, generally of iron. The larger forms of spikes, particularly railroad spikes, are chisel-pointed, and have a head or fang projecting to one side to bite the rail. Spikes are also made split, barbed, grooved, and of other shapes." &mdash;Whitney, 1889
<p>Illustration of a spike that is both barbed and forked.

Barbed and Forked Spike

"A large nail or pin, generally of iron. The larger forms of spikes, particularly railroad spikes, are…

"A large nail or pin, generally of iron. The larger forms of spikes, particularly railroad spikes, are chisel-pointed, and have a head or fang projecting to one side to bite the rail. Spikes are also made split, barbed, grooved, and of other shapes." &mdash;Whitney, 1889
<p>Illustration of cut spike, also called a large cut nail.

Cut Spike

"A large nail or pin, generally of iron. The larger forms of spikes, particularly railroad spikes, are…

"A fin-spine; one of the unjointed and unbranched sharp bony rays of the fins, such as those the presence of which gives name to the acanthopterygian fishes; a spinous fin-ray, as distinguished for a soft ray."
<p>Illustration of the ventral fin of the acanthopterygian fish.

One Spine on the Ventral Fin of a Bony Fish

"A fin-spine; one of the unjointed and unbranched sharp bony rays of the fins, such as those the presence…