A lean patch phrase informal
The phrase is typically used with verbs such as "have", "experience" and "go through".
The adjectives "bad", "difficult", "rough", or "sticky" can substitute for the adjective "lean".
Used to refer to a specific period of difficulty or failure in one's life
Have you ever gone through a lean patch, sir? And how was your feeling at that time?
It is believed that people who used to experience a lean patch in their life are more likely to succeed.
Many people are experiencing a lean patch because of COVID-19 lockdown.