The phrase "what's in a name" took on new meaning for a Hamilton tobacconist fined $5000 for using the word smoko on his store's signs.

Kevin Carroll's company yesterday became the first retailer to be convicted under new smokefree laws.

Carroll's retail chain Smoko's Discount Specialist was ruled to have run foul of the amended Smokefree Environments Act, which prohibits retailers displaying signs indicating tobacco products for sale.

Ministry of Health officials dismissed Carroll's argument the phrase "smoko" was a reference to the popular New Zealand term for tea break, saying the word's use was a "blatant breach" of the act.

Carroll pleaded guilty to five charges of contravening Section 22 of the Smokefree Environments Act, but yesterday insisted he had done nothing wrong.

"When the ministry first approached me about my store signs I went and got legal advice and was told using the term smoko in my signage was okay," Carroll told Fairfax Media outside Hamilton District Court last night.

"Because I've had such a good relationship with the ministry in the past I expected them to engage with me and consult with me but instead I get whacked with a summons to appear in court."

Carroll, a South African, said he felt compelled to plead guilty to avoid a personal conviction at a time he was applying for residency.

"I just feel the ministry has been very heavy-handed and went after me because I have five stores and appear to be growing. I've basically given the ministry the test case they were after and now they'll go after other retailers."

Carroll, who suffered stressed-induced shingles because of the court case, said he had spent $8000 rebranding his stores and removing the word tobacco from his signs.

He would now have to spent another $11,200 on a second rebranding.

Lawyer Jamie Eng, acting for the ministry, said the focus of the prosecution was to deter other retailers from breaching the Smokefree Environments Act.

Judge David Ruth said the term smoko could mean a refreshment break for some but for others engaged in "this disgusting habit" it could have a different meaning.