This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

ad. Once every year without fail, yearly

ad. Yearly; year by year.

Yearly; each year; returning every year; year by year.

ad. by the year; every year (usually with reference to a sum of money paid or received)

ad. without missing a year

"The other four perish or are murdered on the way, so that the thirty thousand annually exported, as stated by Sir Bartle Frere, represents a loss of 150,000 human beings _annually_ from the east coast alone, altogether irrespective of the enormous and constant flow of slaves to the north by way of the White Nile and Egypt."

yearly    perennially   

manually