As used in sections 379.882 to 379.886:

(1) “Commercial casualty insurance” means casualty insurance for business or nonprofit interests which is not for personal, family or household purposes, and which is provided by issuance of a policy of insurance and not merely a binder for such insurance coverage;

(2) “Director” means the director of the department of commerce and insurance;

(3) “Insurer” means all insurance companies, reciprocals or interinsurance exchanges transacting the business of commercial casualty insurance in this state;

(4) “Nonpayment of premium” means failure of the named insured to discharge when due any of his obligations in connection with payment of premiums on the policies or any installment of the premium whether the premium is payable directly to the insurer or its agents or indirectly under any premium finance plan or extension of credit;

(5) “Nonrenewal” means the determination of an insurer not to issue or deliver a policy replacing at the end of the policy period a policy previously issued and delivered by the same insurer or a certificate of notice extending the term of a policy beyond its policy period or term;

(6) “Renewal” or “to renew” means a policy previously issued and delivered by the same insurer or the issuance and delivery of a certificate or notice extending the term of the policy beyond its policy period or term, and any policy written for a term longer than one year or any policy with no fixed expiration date shall be considered as if written for successive policy periods or terms of one year.