Kel Richards writes:
The word skerrick means “a small amount; a small fragment; the slightest bit”. It’s use is almost always negative: we might easily say that we don’t have a skerrick of something, but it would unusual to say that we do have a skerrick – unusual, but not entirely unknown, as in “How much is left?” – “Just a skerrick”. Skerrick is one of those words that began life as a British dialect word, came to Australia with the early settlers, and survived here in colloquial Australian English while fading out of existence in the land of its birth. It’s recorded in Australia as early as 1854 (in a book called Gallops and Gossips) in the statement: “I have plenty of tobacco, but not a skerrick of tea or sugar” (which is, clearly, the modern sense of the word). So, where did the word come from? The 1823 edition of Grose’s Dictionary of the Vulgar Tongue records the word “scurrick” which is said to be thieves’ cant for a half-penny (it’s recorded in the same sense, in the same year, in a Dictionary of Turf by “Jon Bee”). And this word “scurrick” is sometimes recorded as “scuttick” and sometimes as “skiddick” so it is probably the origin of “skerrick” – especially as the meaning seems to match: a half-penny being “a small amount”."