This word consists of kanji with hiragana attached. Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means say humbly, and this is just the verb form, to say humbly. You can also call this to say, just remember that it's humble!

This is a very humble way to say "to say" so it's used in especially formal situations, and only to talk about yourself or your associates. Because of its formality, it's almost always in the ます form, which is 申します.