To look at something. The phrase comes from rhyming slang in which "butcher's hook" rhymes with "look." Primarily heard in UK.

What does it mean to take a butchers?

British, informal. : to look at something This may be what we need. Have a butcher's.

What does the slang term butchers mean?

you have a phrase like 'a butcher's hook' and you find a word that rhymes with hook which in this case is… ... So, to have a butcher's is cockney rhyming slang. And it means to have a look.