[447-54] A frippery was a shop where old clothes were sold. Trinculo has found the clothing Ariel hung upon the line.
[447-55] Under the line. We can imagine that Stephano has pulled the leather jerkin or coat from the line. When he says under the line, he thinks of that as an expression sailors use when they are near the equinoctial line or equator, where the heat is intense, so strong as to take the hair or fur off the coat and make it a bald jerkin.
[447-56] By line and level, that is, as architects build, by plumb line and level. Trinculo picks up the word line and makes a new pun on it.
[448-57] A pass is a thrust; pate is head. Pass of pate is a thrust or sally of wit.
[448-58] Lime is a sticky substance used to catch birds.
[448-59] Barnacles here means barnacle-geese, a kind of geese supposed by the superstitious to be produced when certain barnacles or shell-fish fell into the sea water.
[449-60] Pard is a contraction for leopard; cat-o’-mountain may be another name for wild-cat, though wild-cats are not spotted. Probably the term is loosely used to mean any spotted animal of the cat tribes.
[450-1] Goes upright with his carriage means, goes erectly under his burden, that is, there is time enough to accomplish what Prospero wishes to do.
[450-2] That is, “In the grove of line-trees which protects your cell from the weather.”
[450-3] Till your release means till you release them.