Longman Dictionary of Contemporary English
sick note
noun
EXAMPLES FROM CORPUS
▪ You don't bring a proper sick note when you've been off school.
Wiktionary
sick note
alt. 1 (context UK English) A note from a doctor certifying the patient is ill, and therefore unable to go to work, school etc. 2 (context UK idiomatic English) Someone who dodges work because of sickness, implying they are faking it. n. 1 (context UK English) A note from a doctor certifying the patient is ill, and therefore unable to go to work, school etc. 2 (context UK idiomatic English) Someone who dodges work because of sickness, implying they are faking it.
Wikipedia
Sick Note (TV series)
Sick Note is a forthcoming British comedy series, and is set to air in early 2017 on Sky Atlantic.
Usage examples of "sick note".
If there was an Olympic Sick Note event, he would have been in the British team.