Odd words, old meanings
A cobweb vs. a spiderweb: Is there a difference?
Published on September 20, 2026
How much is a notch when it comes to volume? Who is Bob, and why is he everyone’s uncle? What is the difference between a spider web and a cobweb? Languages change with time and use, and English is no exception, but some phrases remain frozen in time, and while we still use them, we don’t always know their literal meaning. Here are 10 idioms and words that don’t make sense, but once did.
To a T
We often use the phrase "to a T" (sometimes spelled "to a tee") to indicate something done perfectly, with precision. But is it about the letter "T"? Not really. The original phrase used to be "to a tittle," with tittle being the proper name for the dot of the "i" or the "j," and it conveyed the idea of doing something accurately, down to the smallest detail. Eventually, "tittle" was shortened to "T," but the phrase had already stuck, even if its literal meaning was lost.
Fathom
Although "fathom" might sound very formal, we all know that it is synonymous with "understand." But did you know that fathom is actually a nautical unit of measurement? From the Old English fæðm ("the span of the arms" or "embrace"), it represented the distance between the left and right fingertips of outstretched arms. Eventually, a "fathom" was standardized to about six feet or two yards, and was mainly used by sailors to measure water depth. It was this connection with depth that led the word to take on a figurative meaning of "getting to the bottom" of something, or understanding it thoroughly.
Red herring
Popularly, we understand that a "red herring" is something meant to give false clues or distract from another pressing issue. But why a herring? Herrings turn red when smoked and also acquire a strong, pungent smell, which made them a great tool for training hunting dogs, as the smell of the fish covered the trail of the prey. As a metaphor, though, it was popularized in the early 19th century by journalist William Cobbett, who used it to describe how the press was easily swayed by false news.
Rule of thumb
If something is a "rule of thumb," it means that it’s a common guideline, usually based on experience rather than science. In its origins, this phrase was quite literal: thumbs served as a rule. Tradesmen often used the width and length of their thumbs to take and remember measurements, a system that, though practical and effective, only worked for the owner of the thumb in question. Its use as an idiom comes from 17th century writers comparing this popular method with more scientific measuring systems.
Turn it down a notch
If someone asks us to "take it down a notch," how much should we lower our volume? With "notch," this idiom refers to mechanical dials, like the ones used in a radio, where the notches signal the different levels. And while radios only date back to the 20th century, the roots of this idiom go all the way back to the 17th century and to the phrase "take it down a peg," related to wooden pins used for measurements.
Cobweb
Is there a difference between a cobweb and a spiderweb? Although they are synonymous, most dictionaries will make the distinction that "cobweb" is particularly used for dusty, abandoned spiderwebs. But what does the "cob" part mean? "Cobweb" is derived from the Middle English coppeweb, composed of coppe ("spider") and web ("woven fabric"). If we go one step further, coppe comes from the Old English attorcoppe ("spider"), a mix of attor ("poison") and coppe ("head" or "round thing"). So, despite the slight difference in their actual use, "cobweb" and "spiderweb" mean the same thing.
Break the ice
It isn’t difficult to see how "breaking the ice" might have originated from people actually breaking ice, but what many ignore is that this custom (and the phrase) is rooted in diplomacy and trade. When large trade vessels were unable to advance due to frozen rivers, canals, or harbors, it was common to send people in a small boat to "break the ice" and allow the ship to continue its course. In some places, however, locals would send "icebreakers" to clear the path for a foreign vessel as a welcome and a sign of goodwill. The metaphorical use of the phrase exists in many languages, but it was first recorded in English in the 16th century.
Let one’s hair down
The idea of "letting down your hair" is popularly associated with relaxing and letting formalities aside, but the phrase is rooted in an actual Medieval and Renaissance custom. Traditionally, single women would keep their hair loose and uncovered, but would pin it up once they married. It was not proper for a married woman to be seen in public with their hair down, something they would only do in the comfort of their home, foregoing elaborate hairstyles and uncomfortable pins. Eventually, loose hair lost its social status meaning, but the connection with relaxation remained.
Bob's your uncle
According to historians, no one knows who Uncle Bob is, or what his connection is with simple and easily accomplished tasks, but popular folklore claims to have the answer. According to this theory, the phrase refers to British Prime Minister Robert Gascoyne-Cecil (who went by Bob), appointing his nephew Arthur Balfour as Chief Secretary for Ireland, a position he was woefully unqualified for, but that was made possible because "Bob’s your uncle".
Midwife
Have you ever wondered why midwives have that name? After all, there is nothing "mid" nor necessarily "wifely" in helping someone give birth. The answer takes us back to Old English, where mid meant "with" or "together with," and wif (the origin of "wife") meant "woman," "female," or "lady," and not necessarily a married female. First recorded around the year 1300, "midwife" was an accompanying person (typically a woman) who assisted mothers during labor. Although the literal meaning of the term is lost to us, the importance of the role was surely the reason this word survived through the centuries.
