Tesco has a heraldic crest (!).

I did a little Googling, because even though, dear reader, I confess I studied Latin all four years of high school, I knew “mercatores” had something to do with merchants or markets but “coenascent” had me stumped. Lo, some classics geek had this to say in 2009:

The Tesco Connection

Some years ago I was contacted by the customer relations people at Tesco. A customer had, like me, noticed the motto mercatores coenascent on the doors of their internet delivery vans and wondered what it meant. Tesco did not know the meaning of their own motto, but a Google trawl came up with only two hits, one of them being the website I had at the time.

The coenascent will immediately strike latinists as not quite right (it’s clearly a deponent verb, and the -ent ending is impossible), and a quick look at The Oxford Latin Dictionary will confirm that it does not exist. If the motto meant anything, it would be along the lines of ‘merchants will grow together.’ However, the illatinate nature of the verb makes sense to those who know that the founder of the firm was Jack Cohen, and that the first four letters of the Latin are a pun on his name. Jack came up with the word Tesco by combining the initials of tea importer T. E. Stockwell with the first two letters of his own name. I pointed this out to the customer relations people at Tesco and was thanked with a very generous voucher for my efforts.