The Reversed Tilde ∽: Meaning, Usage, and Unicode Guide
The ∽ symbol, officially known as the Reversed Tilde, is a mathematical operator commonly used to indicate proportionality, equivalence, or similarity between two values. Unlike the standard tilde (~), which curves up and then down, the reversed tilde curves down and then up. It serves as a visual shorthand in mathematics and science to show that two elements share a relationship without being exactly equal.
In the Unicode standard, ∽ holds the code point U+223D and lives inside the Mathematical Operators block. Mathematicians have used tildes and their mirrored counterparts for centuries to express complex relational concepts. The reversed orientation emerged as a way to distinguish specific types of similarity or asymptotic equivalence from the standard tilde, ensuring formulas remain precise and easy to read without adding clutter.
You will spot the ∽ symbol most frequently in math and physics textbooks. In these fields, it usually means "is proportional to" or indicates a specific kind of equivalence relation. While less common in casual texting, internet users sometimes repurpose the reversed tilde aesthetically to create symmetrical text faces (kaomoji) or decorative borders in social media bios. In programming, while the standard tilde serves as a bitwise NOT operator in many languages, the reversed tilde occasionally appears in specialized computational math software or distinct mathematical markup languages like LaTeX, where it is generated using the command \backsim.
Typing the ∽ symbol requires a quick workaround, as it does not appear on standard keyboards. On Windows, you can type it in Microsoft Word by typing 223D and then pressing Alt + X. Mac users can open the Character Viewer by pressing Control + Command + Space, searching for "reversed tilde," and inserting it directly into their text. On smartphones, you will not find it on the default symbol keyboard, so copying and pasting from a web page or encyclopedia is the most reliable method.
The reversed tilde belongs to a larger family of relational symbols and is frequently confused with its sibling, the standard tilde (~), which denotes approximation. Other close relatives include the "almost equal to" symbol (≈), featuring two wavy lines, and the standard "proportional to" symbol (∝), which looks like a partially closed figure eight. While they all express a form of similarity or relation, the ∽ stands out with its unique, backward-flowing curve.