cos
cos Lexical Profile
cos Game Scores & Validity
• conjunction
An informal contraction of "because", used to introduce a reason or explanation.
"I didn't go to the party cos I was feeling too tired after work."
• noun
The written mathematical abbreviation for cosine, the trigonometric function equal to the ratio of the side adjacent to an acute angle in a right-angled triangle to the hypotenuse.
"To find the horizontal component of the force vector, multiply its magnitude by cos theta."
British A variety of lettuce (Lactuca sativa var. longifolia) that grows in a tall, oblong head of crisp, elongated dark-green leaves with prominent pale midribs; romaine lettuce.
"She tossed crisp leaves of cos with parmesan cheese and croutons to make a classic Caesar salad."
Word Nuance & Usage
As a conjunction, "cos" (often spelled "'cos" or "cuz") is strictly informal and conversational; it should be avoided in formal or academic writing in favor of "because". In British and Commonwealth English, "cos" is the standard culinary term for what North Americans call "romaine lettuce".
• Rhymes for cos
• Nearby Words
Word Origin & Etymology
The culinary sense derives from Cos (modern Kos), a Greek island in the Aegean Sea where this variety of lettuce was historically cultivated. The mathematical abbreviation is shortened from New Latin cosinus, while the conjunction is a phonetic clipping of "because" first recorded in the 19th century.
Usage Trend
Historical frequency of usage in published text.