Wikipedia does not currently have an article on Semimonthly, but our sister project Wiktionary does:

Read the Wiktionary entry on semimonthly

You can also:

• Search for Semimonthly in Wikipedia to check for alternative titles or spellings.
• Start the Semimonthly article, using the Article Wizard if you wish, or add a request for it; but please remember Wikipedia is not a dictionary.