swing the lead

Từ điển Oxford Advanced Learner 8th

ˌswing the ˈlead idiom
(old-fashioned, BrE, informal) (usually used in the progressive tenses)to pretend to be ill/sick when in fact you are not, especially to avoid work
•I don't think there's anything wrong with her— she's just swinging the lead. The lead was a weight at the bottom of a line that sailors used to measure how deep water was when the ship was near land. ‘Swinging the lead’ was thought to be an easy task, and came to mean avoiding hard work.
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