(A). A cask holding 4 1/2 gallons of ale or beer. This is the smallest of the casks. Two pins = a firkin or 9 gallons, and 2 firkins = a kilderkin or 18 gallons.
Pin
Not worth a pin. Wholly worthless.
I don't care a pin, or a pin's point. In the least.
The pin. The centre; as, “the pin of the heart” (Shakespeare: Romeo and Juliet, ii. 4). The allusion is to the pin which fastened the clout or white mark on a target in archery.
Weak on his pins. Weak in his legs, the legs being a man's pegs or supporters. A merry pin. A roysterer. We are told that St. Dunstan introduced the plan of pegging tankards to check the intemperate habits of the English in his time. Called “pin-tankards.”
In merry pin. In merry mood,in good spirits. Pegge, in his Anonymsina says that the old tankards were divided into eight equal parts, and each part was marked with a silver pin. The enps held two quarts, consequently the quantity from pin to pin was half a Winchester pint. By the rules of “good fellowship” a drinker was supposed to stop drinking only at a pin, and if he drank beyond it, was to drink to the next one. As it was very hard to stop exactly at the pin, the vain efforts gave rise to much mirch and the drinker had generally to drain the tankard. (See Peg.) No song, no laugh, no jovial din Of drinking wassail to the pin.
Longfellow: Golden I sgend.
I do not pin my faith upon your sleeve I am not going to take your ipse dixit for gospel. In feudal times badgas were worn, and the partisans of a leader used to wear his badge, which was pinned on the sleeve. Sometimes these badges were changed for specific purposes, and persons learned to doubt. Hence the phrase, “You wear the badge, but I do not intend to pin my faith on your sleeve.”
He tirled at the pin. Rattled at the latch to give notice that he was about to enter. The pin was not only the latch of chamber-doors and cottages, but the “rasp” of castles used instead of the modern knocker. It was attached to a ring, which produced a grating sound to give notice to the warder. Sae licht he jumpëd up the stair, And tirled at the pin; And wha sae ready as hersel' To let the laddie in.
Charlie is my Darling.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894