Meaning & use
cos
An abbreviation for cosine, a trigonometric function comparing a triangle's adjacent side to its hypotenuse.
See it in a sentence
To find the angle, the student calculated the inverse cos of the ratio.
The calculator has separate buttons for sin, cos, and tan.
A note on using this word
Cos is also British informal slang for 'because', and 'cos lettuce' is another name for romaine lettuce; context makes the intended meaning clear.
Words with a similar meaning
This term is best learned through its definition and examples.
Choose a synonym to suit the sentence. Meanings can overlap without being identical.
Another way to use it
2. conjunction
An informal British spelling of 'because', used in casual speech and writing.
I stayed home cos I didn't feel well enough to go out.
Make it your own
Write a sentence using “cos”, then compare your use with the examples above.