The difference between Beak and Bill

Beak as a noun (botany):

Anatomical uses. A rigid structure projecting from the front of a bird's face, used for pecking, grooming and for eating food. A similar structure forming the jaws of an octopus, turtle, etc. The long projecting sucking mouth of some insects and other invertebrates, as in the Hemiptera. The upper or projecting part of the shell, near the hinge of a bivalve. The prolongation of certain univalve shells containing the canal. Any process somewhat like the beak of a bird, terminating the fruit or other parts of a plant.

Beak as a noun (architecture):

Figurative uses. Anything projecting or ending in a point like a beak, such as a promontory of land. A continuous slight projection ending in an arris or narrow fillet; that part of a drip from which the water is thrown off. A toe clip. That part of a ship, before the forecastle, which is fastened to the stem, and supported by the main knee. A beam, shod or armed at the end with a metal head or point, and projecting from the prow of an ancient galley, used as a ram to pierce the vessel of an enemy; a beakhead.

Beak as a noun (slang):

Colloquial uses. The human nose, especially one that is large and pointed. A justice of the peace, magistrate, headmaster or other person of authority.

Beak as a verb (transitive):

Strike with the beak.

Beak as a verb (transitive):

Seize with the beak.

Beak as a verb (intransitive, Northern Ireland):

To play truant.

Bill as a noun:

Any of various bladed or pointed hand weapons, originally designating an Anglo-Saxon sword, and later a weapon of infantry, especially in the 14th and 15th centuries, commonly consisting of a broad, heavy, double-edged, hook-shaped blade, with a short pike at the back and another at the top, attached to the end of a long staff.

Bill as a noun:

A cutting instrument, with hook-shaped point, and fitted with a handle, used in pruning, etc.; a billhook.

Bill as a noun:

Somebody armed with a bill; a billman.

Bill as a noun:

A pickaxe, or mattock.

Bill as a noun (nautical):

The extremity of the arm of an anchor; the point of or beyond the fluke (also called the peak).

Bill as a verb (transitive):

To dig, chop, etc., with a bill.

Bill as a noun:

The beak of a bird, especially when small or flattish; sometimes also used with reference to a platypus, turtle, or other animal.

Bill as a noun:

A beak-like projection, especially a promontory.

Bill as a noun:

Of a cap or hat: the brim or peak, serving as a shade to keep sun off the face and out of the eyes.

Bill as a verb (obsolete):

To peck.

Bill as a verb:

To stroke bill against bill, with reference to doves; to caress in fondness.

Bill as a noun:

A written list or inventory. (Now obsolete except in specific senses or set phrases; bill of lading, bill of goods, etc.)

Bill as a noun:

A document, originally sealed; a formal statement or official memorandum. (Now obsolete except with certain qualifying words; bill of health, bill of sale etc.)

Bill as a noun:

A draft of a law, presented to a legislature for enactment; a proposed or projected law.

Bill as a noun (obsolete, legal):

A declaration made in writing, stating some wrong the complainant has suffered from the defendant, or a fault committed by some person against a law.

Bill as a noun (US):

A piece of paper money; a banknote.

Bill as a noun:

A written note of goods sold, services rendered, or work done, with the price or charge; an invoice.

Bill as a noun:

A paper, written or printed, and posted up or given away, to advertise something, as a lecture, a play, or the sale of goods

Bill as a noun:

A writing binding the signer or signers to pay a certain sum at a future day or on demand, with or without interest, as may be stated in the document. A bill of exchange. In the United States, it is usually called a note, a note of hand, or a promissory note.

Bill as a noun:

A set of items presented together.

Bill as a verb (transitive):

To advertise by a bill or public notice.

Bill as a verb (transitive):

To charge; to send a bill to.

Bill as a noun:

The bell, or boom, of the bittern.