l

• 英文字母表的第十二个字母，为辅音。表示齿龈边音 /l/，其发音随在词中的位置不同而变化。也用作罗马数字 50、大号（衣服尺码）、升、实习司机标志以及序列中的第十二项。

The twelfth letter of the English alphabet and the ninth consonant, representing the voiced alveolar lateral approximant sound /l/. As a grapheme, 'L' has two distinct allophones in English: the clear 'light L' occurring before vowels and the velarized 'dark L' occurring after vowels or at the end of words. It functions as the Roman numeral for 50, an abbreviation for large size, a designation for learner drivers, a symbol for liter, and the twelfth item in a sequence.

1. The twelfth letter of the English alphabetA1formal

   The uppercase or lowercase character (L, l) that constitutes the twelfth symbol in the Latin-based English alphabet, classified as a consonant. It represents a voiced lateral approximant with two main variants: the clear 'light L' /l/ heard before vowels and the velarized 'dark L' /ɫ/ occurring after vowels or word-finally, as in 'full'. It is one of the most sonorous consonants and can sometimes function as the nucleus of a syllable.

   英文字母表的第十二个字母

   • The word 'lion' begins with a clear L sound.
   • The dark L in the word 'ball' is pronounced at the back of the mouth.
   • Children often confuse the lowercase l with the uppercase I.
   • She wrote a looping capital L to start her signature.
   • Some accents, like Cockney, vocalize the dark L into a vowel-like sound.

2. The Roman numeral for 50A2formal

   The symbol L used in the Roman numeral system to represent the cardinal number fifty (quinquaginta in Latin). It serves as a fundamental component for constructing numbers from 40 to 90 in combination with X and C. This notation appears in historical dates, Super Bowl designations, page numbering, and formal outlines where Roman numerals are traditionally used.

   罗马数字50

   • Super Bowl L was played in 2016, marking the 50th championship game.
   • The number 59 in Roman numerals is written as LIX.
   • Chapter L of the book concludes the first major storyline.
   • The Roman legion comprised approximately L centuries of soldiers.
   • The inscription read 'ANNO DOMINI ML' meaning the year 1050.

3. An abbreviation for large sizeA1informal

   The letter L used as a standard label in clothing, food, and product sizing to indicate a large size, typically positioned between medium (M) and extra-large (XL). It denotes a larger capacity, volume, or dimension. The term has also been adopted in common speech to request larger portions or express a general desire for 'more'.

   大号（L）

   • I need to exchange this shirt for a size L.
   • Can I get a large fries and a L cola?
   • The sweater is available in small, medium, and L.
   • She prefers wearing an L hoodie for a more relaxed fit.
   • The coffee shop serves drinks in S, M, L, and XL.

4. A learner driver plate designationB1informalbritish

   The letter L displayed as a prominent sign on vehicles to indicate that the driver is a learner who has not yet passed their driving test. This usage is particularly common in the United Kingdom, Ireland, Australia, and other Commonwealth countries, where a white square with a red L (or black L on a yellow background) must be legally displayed. It warns other road users to exercise patience.

   实习驾驶标志

   • The car in front had L plates, so we gave it extra space.
   • He's still on his Ls and needs a fully licensed driver with him.
   • In the UK, you must display L plates until you pass the practical test.
   • She was nervous driving with the L sticker for the first time.
   • The driving school's car is permanently fitted with an L sign.

5. The symbol for liter in measurementA2formalscientific

   The lowercase letter l or uppercase L used as the standard symbol for the liter, a metric unit of volume equal to one cubic decimeter. Although the international standard permits both forms, the uppercase L is preferred in the United States and other countries to avoid confusion with the numeral 1. It is a commonly used unit for measuring beverages, fuel, and other liquid commodities.

   升，公制体积单位

   • The soda bottle contained 2 L of cola.
   • Fuel efficiency in Europe is measured in liters per 100 kilometers (L/100km).
   • The recipe called for 500 ml, which is half a liter or 0.5 L.
   • He bought a 1.5 L bottle of water for the hike.
   • The car's fuel tank can hold up to 45 L of petrol.