Noun
Both thickets and thin woodland; (through) all obstacles in a path.
(idiomatic) Both good and bad times.
Source: en.wiktionary.orgI must follow him through thick and thin. Miguel de Cervantes
Of the Budget as a whole, I say "Bravo". I am going to support it through thick and thin. Ramsay MacDonald
We will fight race destruction through thick and thin and never CO exist voluntarily with it. Tom Metzger
According to her, they have both been through thick and thin but they stood by each other and their prayers were answered. Source: Internet
A number of people on social media are used to love stories whereby the couple had been through thick and thin together before deciding to come together as one in marriage. Source: Internet
All of the projects will need and benefit from a committed community of supporters, cheering them on through thick and thin. Source: Internet