the 11th letter of the Greek alphabet
"The mathematician wrote down lambda, the eleventh letter of the Greek alphabet, before continuing his proof."
the craniometric point at the junction of the sagittal and lamboid sutures of the skull
"The anthropologist marked the lambda on the subject's cranium to measure the distance between key suture points."
The eleventh letter of the Classical and Modern Greek alphabet, the twelfth of the Old Greek alphabet.
"In his lecture on ancient scripts, the professor displayed a chart showing lambda as the eleventh letter of the Classical Greek alphabet."
In plain English: Lambda is a symbol from mathematics and computer science that represents an anonymous function, which is code without a specific name used to perform tasks quickly inside larger programs.
"The lambda value determines how quickly radioactive material decays over time."
Usage: Use lambda to refer specifically to the Greek character used in mathematics or computer science programming contexts. Avoid confusing it with similar-looking Latin letters like L when discussing technical symbols versus standard English text.
The word comes from Ancient Greek, where it originally referred to the letter itself. It is a doublet related to the name lamed.