To weigh in means to give an opinion in a discussion or argument.
Even my grandmother weighed in when we were discussing climate change - she said it’s a punishment for our sins.
Owners of small businesses have weighed in on the interest rate debate. Most of them want to keep the rates low for as long as possible.
Don't confuse this expression with to weigh (something) up. This phrase means to consider the advantages and disadvantages of a situation before deciding what to do.
I didn't sleep a wink last night because I was weighing up my options. Shall I move to Australia or stay in Britain?
According to the website guinnessworldrecords.com, the person who has supported the heaviest weight by his neck was the American Frank Ciavattone. He lifted a weight of 366.50 kg (808 lb) at the New England Weightlifting Club in Walpole, Massachusetts in the US, on 15 November 2005.